I don’t know about “pay off quote” charges, but many institutions charge a small fee ($50 seems OK) to actually close down a mortgage. I remember SDCCU used to have that next to the mortgage balance.
But if you are getting rid of a large mortgage, it is better to swallow a little bitterness like this and come out ahead by saving hundreds of $ per month in interest payments that you save.
In future, remember to stay away from banks and use credit unions where they don’t have this moneylender mentality.
