I had the same question.
If you are near a Trader Joe's, they usually have a great selection of Australian, Argentinian but mostly Spanish inexpensive wines.
Spanish white and reds are good, totally drinkable, maybe not memorable but for much much less than $19 a bottle. I consider inexpensive less than $5 per bottle.
Whole foods sometimes has inexpensive wines but their basic wines range $8-15 a bottle.