The wonderfully talented Z does this - I've subscribed to about a half dozen of his projects and he is about to ship out his 2nd & 3rd Freaks commissions (Punisher has already shipped, Clive Owen and Jigsaw are shipping in the next week or two).
The best part about the deposit is that it allows you to jump on board to many projects and allows the sculpter comfort that he has enough interest. Z is also pretty good with allowing time for extra payment where he finished the project early - I needed an extra week and a half to pay for my 3 clive owen sculpts and he has done it.
To be honest though I think a large part of the problem is people like Chris being TOO nice. Artistic types often also hate conflict - they don't want to say no I'm too busy, and then take too much on. I've stated before I think there are too many commissions on going - Chris obviously took too much work on and there is some responsibility on his part - but he wasn't out asking for the work - PEOPLE HERE KEPT PRESSURING HIM TO TAKE IT ON. Some of the chronic commission thread starters need to take at least some of the responsibility. I mean - if you commission someone who has 20 odd commissions on the go (and that was public information), don't expect it to fall out anytime soon even. I think more custom artists need to close their order lists earlier. Because of their dislike of conflict, they tend to also take a "head in the sand" or just plow into the work without realising that it will take them a substantial amount of time to actually wrap it up, and that a bit of communication would take most of the pressure off.
Also with Chris, whilst you could pay in full upfront - he has always stated that he will advise before casting starts and you can still pay then and get the pre-casting discount. I've held off paying him for most of the items I'd want from him and only pay when he's closing off pre-casting. I think I've only paid for my Cameron & House heads even though I want Dexter & Maximus.
People also need to keep in mind that for most if not all of the artists here taking work this is done in their spare time, and in most cases the prices reflect that - the trade off being it will take time (and sometimes alot of time). I have dealt with most of the customisers here on the board for items and it is the rare one that turns something around in under a month, most taking 6 - 12 months. Z is one of those, but I suspect as his work becomes more popular then his timeframes will blow out too - good artists become a victim of their own success as has been seen time and time again with DarkArtist, Les, Soverign Studios, Small Studios etc. They are all great guys, and will deliver the product, but I think people underestimate the sheer volume of work they get asked to undertake on our behalf. I don't think there is any chance of Chris ripping anyone off - he like alot of people has many other competiting priorities.
That said, the ebay thing is a bit disappointing to see.
Just my thoughts on some it.