fleas...ouch

Just last night I noticed Oliver biting his tail and hindquarters with excessive vehemence. I suspected fleas....but didn't look closely. Yep, today at the vet (supposed to be a $30 visit for rabies and one other shot and wormer), vet says he has fleas. So..... $40 bucks for 4 months worth of medicine. I suppose I shouldn't be griping...in Florida I would have to give him flea med and heartworm meds year round. He gets neutered in 3 weeks and shots again, so another $100 bucks out of pocket! Yikes! I cannot afford him and need to put him to work earning money somehow! How about a sled dog when winter hits? A seeing eye dog for the seeing? On the street corner with a bucket in his mouth saying will work for shots and food? Sell his poopy for fertilizer :P??