Only once. I had a Taurus TCP that I bought at the beginning of the year that was not reliable. For this reason I knew for a fact that I'd never carry it.
I also had a North American Arms .22 that had a belt clip. My late father had given it to me several years back and I had shot it a bit. It was not very accurate and I knew I'd never use it either.
I figured there was no reason to have 2 guns I was not emotionally attached to and would never use. So I sold both to one person to fund the purchase of a Ruger SR9c and LC9. I have no regrets as I use both of these regularly and did tons of research before I bought them.
The other guns I have are older ones that have been given to me or passed down and do hold emotional attachment so I'll never get rid of those.