2 bunnies male and potentially female not neutered ( yet, or won’t at all)

Hi everyone. I have one confirmed make 4.5 months boy and 3 months old girl ( confirmed by vet but they want to double check). I have a big playpen and have a divider for them not to sleep together. They play but I separate them for the night time. I heard so many bad stories about neutering went wrong. Also the price for the surgery is outrageous -1200 in my vet clinic. Any suggestions how to keep them healthy why not spraying? Thank you all!