I try to always give a yid parnassah first, and in fact, if I buy from a Jew who charges substantially more than a non-Jew down the street, I cheshbon the difference that it cost me as part of my maaser (yes, yes, I asked a shailah). I would rather spend a little more and a help a Jew. BUT – if the Jew is obnoxious to me when I buy from him, if the service is lousy, and he does not make good on refunding my money for inferior merchandise, then I will not hesitate to go elsewhere. We should support our bethren, but not allow them to cheat us.
