For me, budget wines are those for $15 a bottle or less. I find Trader Joe's Grand Reserve wines to be a very good value generally in that range, though their pinot noirs tend to be pretty mediocre IME.
Ditto on the above recommendation for vinho verde; TJ's has it locally for the $6 to $7 range, and it's fine.
Columbia Crest Washington State cabernets, especially their H3 label from Horse Heaven Hills area vineyards, tend to be very good values.