There's nothing "wrong" with a cheap bag as long as its not a knock-off of something else. I see cute enough bags in cheaper labels like Nine West, Fossil, and Liz Claiborne. Hmm... I guess I would have to say that I would only buy a cheap bag if it was super cute and something that I wouldn't plan on using for more than one season.
I think this Fossil bag would be super cute for summer... but I would probably get sick of the dots after awhile:

Allie Mini Hobo $58
And I think this Nine West clutch would be super cute for going to a wedding or something. I wouldn't use it very often... so its reasonable to say I wouldn't want to spend a ton of money on it.

Broken Glass Small Clutch $39.99