Advice Please, with picture

I'm not sure what to do. My beloved kitty has something growing on her foot. She has had this her whole life, a small pink pimple on the top of her foot. When she was a kitten (she is 8 yrs old now) they biopsied it, and the biopsy was inconclusive. THe vet said it was some kind of 'mass' and it might possibly be cancer, or maybe not.
THe cat was in so much pain from the biopsy, we couldn't torture her any more, and it was going to cost $2,000, so we just let it go, did not get it removed, and she's always had this little pimple.
Well, in the past few weeks, it has grown. I have attached a picutre.......
she does not appear to be in any pain, she is totally happy, running around, etc.........it doesn't seem to bother her....although sometimes she bites it while she cleans it.
If we take her to the vet, they will definitely hurt her with needles.....and what can they possibly do if it is bad?
Should we take her to the vet? If we do, they will DEFINITELY WANT TO REMOVE IT which will torture the cat, cost a ton of $, and after all that it may be nothing. And if it is something, what can they possibly do?

Should we just keep an eye on it and make sure she is not in pain, it doesn't grow, etc. OR, should we do something more drastic?

Have you ever seen anything like this?

Please advise......

but there isn't anything that promises....other than torturing the poor cat.....
even if they remove it, that won't fix anything......and she is NOT in pain....so why fix something that can't be broken?
She's had this HER WHOLE LIFE.....it just grew a little.

Look at it this way...what if your DH had a growth on his hand...he'd had it his whole life. When he was a kid, the doctor tried to remove it and it came back. Now it has started to grow. It doesn't hurt him, but has grown in the past few weeks. What would you do? I'd hope you'd recommend he go to the doctor to have it removed.

Take your kitty to the vet. There are medications that can help with the pain. Wouldn't you rather have her in pain for a few days and find out the growth was nothing than to leave it and discover too late that it was cancer?