Based on my 2 year experience, I'd say the way to get great grapes and not over pay, is to pick it yourself. All the wine I made this year was picked by me and friends and family. About $0.50 per pound is the usual going rate. The only exception is if it's a big name place like Napa Valley where the price is $4 per pound. That's ridiculous. But there are dozens of less well known, but equally high quality grape growing areas here in Northern California.
But if you're removed from the source, it's going to cost more.
@Johnd got about the best deal out there for fruit shipped off the west coast. It's funny, I was at Truitt-Hearst yesterday in Sonoma, and ran into a guy from Philadelphia. And he was telling me "a lot of guys in Philly, get Lodi fruit." Like I would have never known that. LOL. I could not help but think of
@Ajmassa5983. He was telling me he and his wife spend a month every fall in the wine country. Pretty cool that it's that strong of a draw for them. I was thinking he should stay home and make his own wine!