Seems to be a fine piece of work so figure in the 6 figure USD range. Now if you outsource it you might cut it in half but then you are on flights to other parts of the world, hotel bills and such so my bet is you end up at 6 figures again.
The problem is that if you copy a site you are going to open yourself up to lawsuits so maybe another 6 figures to the lawyers.
Does anyone have a clue as to how much it would cost to develop a site on the scale of vrbo.com?
I have the opportunity to take over development of a site similar to vrbo.com but with a different angle. The previous developer took the upfront money($4,000) and ran. I'm thinking he ignored bids with a realistic bids and went straight for the "too good to be true" low bid. I'm trying to convince the potential client that a site on the scale of vrbo.com is a huge investment and he should severely reduce his requirement to match his budget.