As a matter of fact, a couple of the very well to do from a City near mine, appeared in my particular Salvation Army one day. We waved at each other from a distance, almost a wink, 'cuz they'd caught me coming out of their local "2nd hand place" the month before.
A bargain's a bargain -- doesn't matter what income class you are in.
What I love about the one close to work is it's the cities central hub store, so it usually has the best stuff.
And I don't feel guilty if I buy something goofy I've been wanting to try (Bread machine). If it doesn't work out, I bring it back. But most of my house is decorated in Early Goodwill.
The best shopping trip I ever took in my life, in terms of fashion and value, was to the Goodwill in Carmel, CA. The most fun visit was to the Goodwill in New Orleans--full of Mardi Gras costumes and masks.
I found I've collected too much stuff, and spend too much time picking up. Lately, I've been shopping in my own home--discovering something ignored, enjoying it one more time, then donating it to the local Salvation Army.