Iron Man is the poster child for this in the Marvel Universe. He also provides The Avengers and many other superheroes with financial assistance or expensive resources whenever they need it. Which is often (it sometimes seemed that the Avengers couldn't go more than a couple issues without someone throwing out the line "Tony Stark will pay for that!" to an irate citizen whose property had been damaged). This also means that it's kind of a big deal whenever Stark's finances are impacted enough that he can't afford to finance the Avengers, or even himself. The Bendis run on New Avengers has him struggling to pay the salaries of the various Avengers after his business ventures took a hit, and Gerry Duggan's run on Tony's own book partly involves him struggling to be Iron Man after getting ousted from Stark Unlimited and losing most of his assets.
Young Avengers: Kate Bishop, back when the Young Avengers were just starting out. At the end of the first arc, she sets the team up in a run-down building owned by her family's business and uses a few connections in the fashion industry to replace their ruined costumes (or, in her case, just make one). She's moved away from this since then, however, and as of 2017 her father is being built up as one of her enemies.
To a lesser extent, the Fantastic Four are a rare superpowered example, living in a penthouse apartment and funded by the proceeds from Reed Richards's patents. It's debatable whether they count or not as they primarily use their super powers to fight crime, and their money to support charities and advance science. They do use some expensive gear like the Fantasticar, and dimensional teleporters. Oh and they have a robot. On at least one occasion (following an abortive counter-invasion of Latveria) the Fantastic Four lost everything. It barely took Reed any time at all to file enough patents to make their entire fortune back.
Professor Xavier, founder and mentor of the X-Men, can't always directly fight crime (paraplegia is a bitch that way), but he still uses his mountains of cash to help his students do so. Well, that and his absolutely immense amount of Psychic Powers, anyway.
One such student, Angel/Archangel, has enough money that he wouldn't need the Professor's, though he's seldom seen to use his resources to create gadgets, etc. However, when he was a solo hero, he did have that stun pellet gun. He once solved the problem of Vanisher developing and selling a dangerous drug by simply buying out his company. During his time away from the X-Men, he's also funded the other teams he's been a part of, most notably the New Defenders, Uncanny X-Force and the original Champions.
As Xavier's "strongest telepath in the world" title often tends to fall into the murky realms of Informed Ability, one could argue that his deep pockets are in fact his primary superpower, with his actual telepathy being a "secondary mutation" as they are called in the X-books. Indeed, Xavier's ridiculous and improbable (it's never quite explained where all his money comes from, except with the occasional Hand Wave that the Xavier family is Old Money) wealth is even lampshaded in-universe, with the loner character Dr. Nemesis initially turning down an offer to join the X-Men because "I won't be bought out by you dilettantes with your bottomless bank accounts."
Sunspot of the New Mutants recently did this after Secret Wars (2015). He is fantastically rich, owning a Brazilian TV network and a large chunk of the land. So he easily had enough money to buy out the science crime organization AIM (these are the guys whose past projects include making the Cosmic Cube, Super-Adaptoid and M.O.D.O.K.) after he realized that they'd be more than happy to turn their science to benevolent aims so long as they have the money and not get assaulted by mutants, super-soldiers and/or sociopathic vigilantes. He ran as one of his own enterprises as well as a personal HQ and scientific think-tank (he has no brains for mad science so he used theirs) for the New Avengers (2015) and the U.S.Avengers.
X-Factor saw a similar episode to the one above about The Juggernaut. A mercenary who was already shown to be as tough as the team walked into a hospital to take out a target. Havoc walks up looking to join the fight only to pull out his checkbook (government account) and end the confrontation rather than level the hospital.
The Punisher fits into this in a way. While he doesn't really have any huge reserves of cash, he doesn't mind appropriating any loose change from the criminals he kills and using it to finance his continuing war on them. Since some of the criminals in question are wealthy mob bosses and the like, this sometimes comes to a significant haul. In addition to their money, he also appropriates their weapons, vehicles, and any other portable goods that might be of any value to him, which cuts down significantly on his overhead costs.
Danny Rand, Marvel's Iron Fist, is a glorious aversion. He's a billionaire superhero whose crimefighting has almost nothing to do with his being a billionaire: he's the heir to the Iron Fist, a set of martial arts based abilities. Not only do these require no financial resources whatsoever, he's best known as being, along with Luke Cage, one of the core Heroes for Hire. Similar to Batman, Danny gives huge amounts of money to charity. A recent development in his book is that he's converted Rand International solely into a charitable organization, which he intends to run until he's "Able to die poor."
The civilian identity (well, one of them, at any rate) of the B-list Marvel hero Moon Knight is that of a wealthy businessman who owns and operates his own corporation, the money from which he uses to pay for all the fancy weapons and other devices he uses in his war on crime. Unfortunately, he is what you call "cash poor"; he has wealth but getting a significant portion in cash on short notice is harder than he anticipated when he was facing a ransom demand.
The only reason that the Great Lakes Avengers were able to survive (up until their official status) as a superteam was via Big Bertha's superpower: her ability to control her body shape. Crimefighting, she grows huge and strong enough to bounce bullets and semis. Day job? Supermodel.
Kyle Richmond, also known as the superhero Nighthawk, uses his vast fortune to sponsor The Defenders, a second-tier team of heroes. As just one example, when Luke Cage complains that his helping the Defenders is taking away time from his paying work, Richmond offers to put him on retainer and pay him a salary to stay with the team, an offer which Cage cheerfully accepts.
Black Panther may have inherited his powers, but his incredible wealth and political power are some of his greatest advantages in crime fighting.
Inverted with the X-Men character Arcade, an obscenely wealthy Nightmare Fetishist who uses his vast resources to become a super-villainFor the Evulz. Ostensibly, he's a Professional Killer, but his Murderworlds cost so much to build and maintain that — even at a standard fee of $1 million a hit — he never turns a profit. He took it up a notch in the Avengers Arena series, in which he bankrolled the creation of a Murderworld the size of a small country in Antarctica, in which ultra-high-tech devices granted him Reality Warper powers on the premises.
Another inversion is the Spider-Man villain Angelo Fortunato, a wannabe Overlord Jr. whose mobster father bought him the Venom symbiote outright during a period when it was separated from its usual host, Eddie Brock. Don Fortunato intended for his son to make a name for himself, but unlike Arcade above, Angelo couldn't even rise to supervillainy and was ultimately abandoned in midair when the symbiote judged him as too weak to be its host, leading him to fall to his death.
In one issue of Excalibur, Captain Britain proved that the only thing that could stop the Juggernaut...was a check bigger than the one he was expecting from his "client".
