Our conclusions? Yes, freelance sites suck. Do providers want something else? Hell yeah! Do buyers want something else? Hell no! Simply put; being able to first try to get your project done for $100 while you know the real price is at least $20k+ is compelling apparently. I know companies who had stuff we quoted for $50k done for $1k. And it didn't even suck too badly. Why? Because there is SO much competition on those sites that 'newer' providers have to compete on price to get anywhere. So you can get occasional solid work for 1/50th of the price. Especially if you know what to look for.
Then if it doesn't work you just go 5x that, doing it for $5k and most likely you'll have your $50k project done nicely. Note that most companies under $10k price point are willing to go no-cure-no-pay, meaning if it failed so far, you didn't pay a cent yet.
If you get farther than this, yes a different method would be better, however, most don't get to that online or they already have their preferred teams, meaning this won't help them. I already know that if I pay a Ukraine team with 400 5 star projects $50k I WILL have high quality; why do I need these moderators?
I'm not against this at all mind you; like I said, we thought about this seriously ourselves but we just didn't see enough interest from companies. Basically most companies on freelance sites who want to buy something still suffer from that Elance-Digg-syndrome; pay very little for top-notch stuff. And often you do get that.
Also for that $50k the site is worth, you can for instance put 6 teams for $5k on it, having a quite high (from experience) chance of success in at least 1 or 2 of them and banking $20k 'profit'.
I wish you luck but it's a very much uphill battle!