At least between, say, $3 and $6 per bottle:
Supplying wine to sell at $5, $4, $3 or even two bucks per bottle is not that difficult once you set out to do it. Cheap surplus grapes, cheap surplus wines, low-cost winemaking processes and economies of scale all contribute to extreme value supply. Nope, supply is easy. The challenge, until recently at least, has been selling the stuff.