If I asked someone in another area to buy something that I can't get at home and bring it to me (or mail it to me) - I'd pay them. I'm thinking like a bottle or two of a hot sauce that I can't get where I am living (we moved a few times in the military and there were a few things that we picked up when visiting "the folks" because it was NOT available where we were stationed).
Same thing if I was looking for an out of print book or something similar.
But I want to pick out my own appliances, lawnmowers, clothes, and the like, thank you very much! If I didn't make arrangements specifically for you to buy it and I would pay you back - then the buyer can take it back to the store to return it, not ME!