i can usually tell the difference. i think most of the trader joe stuff is seriously defective cr**. i do, drink a lot of rose in summer. i actually prefer a number of the $7 or so to the mid priced, and i dislike the +20 rose.
i also think most of the cameron hughes cheap wine is garbage. every now and then he acquires something decent as distressed merchandise, but most of his fill ins are really really bad.
for a decent $10 chard, taste through the Argentinian. some of those are really good. also look for an aussie Riesling.