I believe that figure of how much you can spend today takes into account savings goals as well as payment commitments.
Also there is no reason you can't look and see you have some money that is available and toss it in a savings account. Basically the user gets to choose where that money goes, but either way they have a better idea of "what's left over."
I would love to see this for (unused disposable) diapers. I bought wayyy too many 1s and have a bunch left over that I will never use. I wish I could send them into a service and get some 3s that I could actually use now.
The thing I noticed was that you can't pick and choose what you like (maybe I misunderstood). Basically you just get a random dress or outfit. If this were truly a netflix style system, you should be able to choose the latest fashion and swap in and out as much as you want. The benefit is the latest fashion for less. That being said, I really like the concept.
In NY when you see a place with a line you get intrigued. Sometimes a queue is a great advertisement for people walking by.