ARC get all their single boys neutered so they can be paired up with girlies before they are re homed. I would certainly agree bring him in for a few nights, put towels in part of his area so he has something soft and warm to lie on, provide lots of tasty treats to tempt him back to eating as soon as possible. check the wound regularly for the first few hours, then twice a day after 24 hours post op for signs of redness, oozing, infection, gaping. It is rare for them to develop problems.
Your vet does sound very expensive to me, I would also suggest ringing about to find cheaper vets, another idea would be to contact a local rescue and see who they use ... they will have a vet who is experienced with neutering small animals. The vet we use will charge you about £40 and will take them in the night before if dropping off the morning of their operation is a problem.