Whilst the idea of a 'Supervillain supermarket' is not new, this is a good presentation of the concept that has been thought through in some detail.
The basic concept is simple. Supervillians do not operate independently, at leas, not all of the time. They need hirelings, they need items you cannot buy off the shelf and so on. So they have to go to an organisation that will supply their needs, no questions asked, cash on the nail, thank you very much.
Novel features of Crime Unlimited include its mobile nature. They prefer to operate out of a club or bar, but shift location every few weeks. It's almost a status symbol amongst the supervillain community to know where they are this month. Once accepted as a customer, you can literally get just about anything that you need - but don't cross them: they don't like that and tend to react forcefully, indeed terminally.
Adventure seeds around them are provided for both Hero and Villain games. For example, you don't always have to pay cash for that weapons grade plutonium you need to fuel your death ray, if it suits them they'll have you owe a favour instead. But they might sell that favour on to someone else... Or ask you to do something you really don't want to do.
Plenty here for you to weave into your adventures, complete with main characters statted up for Heroes Unlimited. If you play a different super-powered game, it shouldn't be too hard to re-stat them, and the concepts will, of course, hold good.