Tumors around the tail of my GSD? Vets, Please. Or those who have been through this.?

My Mason is 8 years old, not a gray hair on his body, has one fast one slow growing tumor around the base of his tail. Yes he has been to the vet, they are not fatty tumors. No he is not neutered. I would like to know of similar situations of male dogs and what you did. Or if by a vet, what are some of the pros and cons of surgery on this sort of thing. My brain tells me there is much more to these tumors than meets the eye. The area, the fact he is not neutered, and some prostate problems that tend to recur. This animal is the love of our lives, but hubby has been out of work for a year. We need some honest and knowledgeable information. Cost, prognosis, and quality of life. These questions I am also putting to my vet.