Well, with my daughter's kitten a few years back who was mono and had just the one undescended, cost us £180. Mind you, this was for antibiotics, etc., because it was major surgery.
I'm not concerned about him being like this, but I'd like to know for sure that he's a male. The furr is fairly bushy down there, and still a bit matted with muck from the garden he's been in. He'll only let me have a few seconds to look and cleaning it would be impossible at the moment.
I also haven't named the little tyke yet and I'm awful at choosing genderless names.
I suppose there's nothing for it but to wait and see.
When he gets rehomed, it's doubly important he gets neutered because he's at risk of cancer. So we'll have to be doubly sure about his new home and feral kitten are tough enough to home anyway.