IN COOKING, cheap wine works fine — in fact, just as well as expensive wine:
Over all, wines that I would have poured down the drain rather than sip from a glass were improved by the cooking process, revealing qualities that were neutral at worst and delightful at best. On the other hand, wines of complexity and finesse were flattened by cooking — or, worse, concentrated by it, taking on big, cartoonish qualities that made them less than appetizing.
It wasn’t that the finished dishes were identical — in fact, they did have surprisingly distinct flavors — but the wonderful wines and the awful ones produced equally tasty food, especially if the wine was cooked for more than a few minutes.
So save the expensive stuff for drinking!