hmm.... I wouldn't pay $500 for that. It seems kind of shady to me. If you look at the other industries, they all have the exact same screen shots and features and everything. This isn't auto detailing software, it's just small business software. A lot of what you are paying for there goes into the part of the software and managing employees and everything.
I think most detailers here are small, either solo or 1-3 employees max. Having a single program would be nice to keep it all organized, but IMO you can probably find some other software to do what you need, and get it done easier. IE you can use outlook with a PDA to do all the scheduling, you can use quicken for all the business side of it, and excell for doing esimates and stuff. If you really wanted to you could get all of this stuff for free via linux.
What kind of functionality would you want detailing software to have? I'm thinking it just needs scheduling, cash flow stuff, inventory, staff, estimates. Nothing too complex. I don't think it's worth spending that kind of $$$. If your going to spend that much get some real business software, like quicken (or Quick Books)