I don't know about prices for this kind of surgery. Other people here may know more about that. But if $7000 does end up being the going-rate, sell anything you can raise some money on. Sell your car, your antiques (if you have any) do a garage-sale, sell your digital camera on ebay, anything else you've got, whether you think you need those things, or not...... do what you really want to do in your heart, for this dog. You would not be happy if you didn't.
$7000 is NOT the going rate. If you have a Veterinary Teaching Hospital in your area, check there first. Call around.....The surgery should be more like $3000. In my experience, the first half of payment has to be paid up front. The second half can be paid out in other ways. If you trust your regular Vet, ask him/her to help you find another place to do this surgery. Good luck.......Karla