Help--I need some recommendations

As some of you know, I teach a wine class at Indiana University South Bend. We're wrapping up on Monday night (10/31), and one of the topics I want to cover is "bad wines." The wines we have sampled have generally been good quality wines, and I think it would be helpful if the students could experience what we would call bad wines--wines that lack structure, balance, etc. If you know of an inexpensive ($10 or less) wine that is widely available that you feel has some significant flaws, please let me know. Put differently, if you were going to explain to a friend the difference between a good wine and a bad wine, you'd pick a wine out of your own collection perhaps to be the good one, but what would you pick to be the bad one? Hmmm...seems like a potential Wine Blogging Wednesday theme to me.