One of my freshman roommates told me about sunk cost. It is not something I have an easy time accepting. I'm thrifty. I like negotiating the most for my money.

It is going to have to be my mantra. Sunk cost.
I need to remind myself of it over and over.
I've invested so much. The lost investment OVERWELMS me.

Sunk cost. Sunk cost. Sunk cost.