i think that Scriptlance should change the way that contests works and force the buyer to choose a winner and pay to  him, if not they can steal ideas, it is like a free brainstorm...

I saw several bidder is bidding just like free for any client making it very hard for calculating actual project cost. Is it not lose for both scriptlance or serious bidders? The job which can not be done less than 100$, freelancers posting only 10$ ????????????? How can it be possible?
My suggestion:
1. Hide bid amount for each project
2. Make budget mandatory for all fixed projects.
3. Should have something which will stop employer to get service almost free of cost or being cheated.

If buyer is allowed to escrow with poor rating it will be in high risk to get transferred once released. So, Scriptlance should ensure a risk free payment

Forcing NEW buyers to post projects limited to verified and certified freelancers will decrease the chance of failure for the buyer's first project.

This could apply to buyers who signup up within X days, or only for their first Y projects posted.

Display the Project Cancellation Ratio in anywhere in front page so that a Programmer can get an idea before he cancel any project . 

Display how many concurrent projects has the coder in hands. Its frustating to select someone and then realize that he is working in another 3-4 projects at the same time.

It happend to me many times, and I'm sure that other buyers should have the same bad experiance, to select a programmer and later on, to find him working on other projects too. Result? Getting emails from the programmer asking for something that is not on my project, or big delays on delivery. Worst than all (that's why I'm asking to not allow bids in other projects), when you face the problem to have the coder disappeared or delaying in replies, because after eg my cheap project of $100, he awarded a new one of $1,000.