... Thrift stores are supposed to sell cheap goods to lower income people...
Well, not any more. Most thrift stores are affiliated with some charity (although I think many of the "charities" are little more than fronts) and the stores rationalize their prices by saying the buyers are supporting the charity. Good Will is bad about that.
Frankly, I often don't care a hoot about their "charity." As I am a agnostic/atheistic humanist, it rather bugs me that some people use their "Christianity" to sell something, and it seems that Good Will does that, too. If it's not a sweet deal, and/or worth the chance I am taking the thing is not working, I will pass.