Both of my boys were neutered for $350-400 each, which included a 36 hour stay at the MSCPA hospital, bloodwork, pre-op exam, pain meds, antibiotics, and a emergency follow up care if needed. So I think it really depends on your situation. If neither one have been to a vet before they get neutered, I would suggest going with the more expensive option and getting the bloodwork done. The bloodwork can help them determine if there’s any reason physiologically why they won’t be able to operate on your buns, as well as making sure their levels are all normal.

I got mine done for with the MSPCA clinic for $150. That option didn’t include a preop visit so I just scheduled a vet visit with a local vet a week before to make sure everything was looking okay which came to a total of $210. I had a post op visit tentatively scheduled but he recovered so quickly and easily that I ended up cancelling it because I didn’t think it was necessary. I liked the idea of doing it at an animal rescue like MSPCA because I was sure that they’ve neutered soooo many rabbits which made me feel more comfortable personally. 

I got my Holland Lop neutered at my vet for only $120. My local HRS partnered with them and they do a low-cost spay/neuter program. According to the HRS, males can be neutered when they’re almost 4 months and females at 6 months.

I live in the UK, so my experience of price probably isn’t relevant (around £100 for either sex, including two post op checks), but I would say 4 months + for boys and 5 months + for girls.

I would also recommend you separate them, if they’re still together and if you don’t know the sex, as you could easily end up with baby bunnies! They may also start fighting when they become sexually mature.

I would ask them both how many spays/neuters they do, and what their survival rates are. An experienced vet should lose far less than 1% of the bunnies they operate on.

Again, you don’t mention if they’re living together, but it really is important to separate them early.