Vet refuses to test growth on my dog

I brought my 13 year old Yorkie to the vet today. For context, his old owner died a few months ago and her daughter couldn't take care of him and I'd just bought a house so I had the room and love dogs so I volunteered to take him.

I've been to this vet 3 times, and each time I've had to wait over an hour from my scheduled appointment time to have him actually seen.

We're in this time because he developed a large black growth bigger than his paw pads on his leg. I wanted to get it looked at because I'm obviously concerned about my baby.

The vet looked at it, thought it was a cyst, and then used a two needles (a smaller then a bigger one) to try puncturing it. Nothing came out except blood, so she said it isn't a cyst.

But she also refused to do a needle aspirate (cell collection) or biopsy of the lump. Just said "I'm sure it's an old man lump", charged me $50, and sent me on my way.

Do I get a second vet''s opinion? Is this normal for veterinary places? I just want to do the best I can by my little guy and I'm feeling frustrated by what I perceive as the lack of care but maybe I'm just under educated in this field?