[DvlshAngel985]

Good response!
I just wanted to add that they also try to match the pup to the right home. If it's an energetic dog, then an apartment life wouldn't be a good fit, unless the new potential owner leads a very active lifestyle, i.e. morning runs that the dog can go on, lots of hiking, etc. Or if the dog is mellow and doesn't need much outside time, then an apt would be a great fit. Also, since you do live in an apt, they will check your rental agreement/contract to make sure that you are allowed to have a dog.
As for the high fees, it is my understanding that these dogs don't always come in great shape. Some come in with serious medical problems, some just need a good haircut, others need some serious training to help correct unwanted behavior which could make them less desirable to potential adopters. Plus, feeding and boarding them while they are in the shelter, or rescue's care. Either way, that costs money. While the pup you might be looking at might not have such a tragic history, others do, and the donation the rescue receives from your pup will go to the care of another.
Like livingdustmops said, they just really want to minimize the chance of this dog, or any dog in their care, will be sent back to a shelter and the money is to help their continuous efforts.