They're 20k a pop, they need a location, an internet connection and I would imagine that they need some maintenance to keep them running. So, they need to see a fair bit of volume to cover the costs, but if you had a few good locations I think you could see a good return.
If you offered a reasonable profit sharing scheme for investors (or funders), I don't think it'd be too hard to get fully funded. But, there's quite a lot of work involved.