The I use to I live in charged an extra $20 a year per dog if you want him to keep his junk. The best part is the issue a different colored tag for nutless dog (blue) and nut packing dogs (red). It was great when walking my Lab, he proudly wearing his blue tag (and his nuts) and seeing most with red tags. I don't plan on breading my dog but I figure as long as I'm a responsible dog owner and don't let him run the streets he should be able to keep his junk. My Rot was spayed when I got her otherwise I would have keep looking for a male.
Where we live now there is no additional cost for letting my dog keep his junk.