That is a pretty fair price for Southern Ontario, but being in London I thought it might be a bit less. It is important that they know what they are doing, as neutering a rat is different to dogs and cats.
I have had almost two dozen boys neutered, and only had two boys that it didn't make totally different rats - Reggie and Abu-boo. Eventually, when both were older ratty men, they did live with other rats but it wasn't until they were much older.
For all the other boys, the difference was day and night, and some of them were biting me as well as other rats.
Some of my boys were much older when the procedure was done, and they came out of it with flying colours and took the same amount of time to recover as the younger boys.
Any surgery carries risks, but I would always suggest neutering an aggressive boy.