TBH, you ad doesn't say much about cost. It's pretty easy to do everything that your web-based will do, but not all in one place, so the cost would have to be semi easy on the brain. Reason is $60 for unlimited use over several years (until you reach your upgrade limit from what I understand). People aren't going to want to pay $25 to write, track record and master a song online even though they probably spend 3-5 times that (or maybe much more) by buying and maintaining the equipment and software to do so.
The costs for treating your room, buying your gear and mikes, interfaces, monitors, headphones, etc. will still be on the person recording, so all you're missing is the actual DAW and plugs...unless you get a huge community that's willing to share/collaborate/buy/sell their stuff, it's probably not going to fly. That's not likely to happen without the large community. Catch 22 YMMV.