Just remember in most things you get what you pay for, while those Freelancing sites are cheap they are rarely quality and most people I've known who have used them normally have loads of issues to fix.

What was your brief to get the quotes from people, the tighter the brief the better the estimate.

If it was "I want a property website" your going to get quotes ranging from a couple of badly designed web pages, to a whole Estate Agent mangement system which looking at your quotes is exactly what you got.

Jen