Hi I have had quite a few guineas over the years &I have only ever had girls. When I read up on piggies before I got them I often found that girls were written to get on better with each other without fall outs &to be fair I have only ever had to return 2girls because they would pick on my original girls each time. They are the only 2 I have ever had fight.
But bonded boars are very close to each other &there's no reason not to consider boys. Although probably better to get a rescue to help with bonding them originally. Its not guaranteed that 2brothers will stay lifetime friends.
Anyway -back to ovarian cysts. I have had one confirmed case of cysts &maybe one or possibly 2 that I think in hindsight probably were ovarian cyst cases.
Ellie was 6yrs old when diagnosed so had hormone injections approx £40 per course of 2injections about 7-10days apart (£20each )
About a year later she had another course of the same. (I have read that these can cost £50-£60 at some vets).
I am incredibly lucky that my vet is cheap in comparison to lots of vets, the only trouble is they are not exotics specialists &I think my guineas are probably the most regularly seen in the practice &I sometimes find I have to hint at ideas for them to consider, although they are very accommodating to my suggestions.
Add on the consultation fee, ultrasound scans & painkillers.
The original vet visit - trials of meds&ideas through to diagnosis if its not a textbook case.
Possible spay if its complicated, etc.
These can all mount up
But in my case only 1 confirmed case in many years.
As mentioned above boys have there own sets of health issues &problems. Stones being one of them.
Good luck in your choice- I'd say its justpersonal preference in the end.
Try phoning a few vets for prices &experience on guineas. Also which conditions they see most regularly. Should give u a better idea.