Before doing anything else have a WR2 expert check out the bike. If you have bought it from a specialist scram shop and it's in as new, PERFECT condition then there is a slim chance that it could actually be worth close to this much. But you would have to really love WR2's to pay this.
Refer to SR post http://main.slackriders.com/Forums/viewtopic/t=37115.html
If not, you're much better off letting go of your deposit.
$750 loss is much better than $2750 which will be the minimum you will lose if you ride the bike out of the shop. (the above not being the situation)
If truly kena conned