Vet Pet Peeve

I got a post card in the mail saying it was time for me to take Diesel in to the vet for his heartworm checkup, ok, fine, good. Well, he has a little growth on his front shoulder and I thought I would have it looked at while I was in there, no biggie. I called and made the appt. for the heartworm testing and took him in. They did the test and such and I asked the vet to look at this little growth. It ends up he has something called a HISTIOCYTOMA. The vet told me it would be X amount of dollars to have the growth removed, however, it could possibly go away on its own within 2 or 3 months. Ok, fine. Well, when I went to pay, they charged me for an office visit! They don't charge for a visit when you are getting any testing done and she did not do anything except LOOK at the growth and they charged me $28 for that!! I am really irritated and I did call around and ask another 2 vets if this was a common practice. Both replied,"No. If your pet is in for something that has a fee (aka heartworm test, shots, whatever) you are not charged for just LOOKING at something." Both places also said, if they did anything, like aspirated it or took a sample, that would have additional charges, which I fully understand. I know these people went to veterinary school to have a career and make money, but I think this was an unfair charge. Has anyone had this happen or experianced anything like this? I am tempted to find another vet because of this, however, I would STILL have to pay for another office visit. I know pets cost alot of money to take care of and I am fully and totally fine with this, they are like children. I just really think this was an unfair charge and I am pissed. I didn't say anything at the time, I was kinda shocked, but the more I think about it, the more irritated I get. I mean, it is already expensive enough, but 28 bucks for some "eyeballin'" is a little steep to me.