I'd be happy with 14 Hands. 14 Hands makes great wine and I can get it for ~$10-$11 a bottle (plus tax) at my local grocery store here in WA. I'm sure Delta could get a bulk discount.
That said, I'm not enough of a wine snob that I find the wine in FC intolerable.
ETA: also, consider that Delta operates ~5,000 flights per day. Even if you assume 2 bottles of wine consumed per day per flight (some more, some less), that's $5 extra x 2 x 5,000 x 365. That's nearly $20,000,000 extra per year you're asking them to spend.