wow that is crappy news
I would get a 2nd opinion too and estimates in writing. I've not had any vet experience yet with hedgehogs but I do have a ton of experience with canines. Vets will often include costs that you do not need in estimates and from one clinic to another costs can vary in extremes. Many will also include day care / overnight stays ~ching~ and nobody is even at the clinic all night with your pet. Some do have attendants but most only have a tech drop in every 4 hrs. I always take my dogs home so I can watch them closely (but I am also comfy doing sub-q fluids and such if needed)
At this point as a hedgie newbie I would not know where to start with after surgery care.
Sorry to hear your bad news and sending hopes your girl will be well!!!