I have managed to check out most of the Everett/Chelsea area wine grape sellers since the beginning of the season. Most of the grapes offered are from larger packers in the Lodi Area and I didn't bother with packaged juice, but all of them offer it too. There are some other options that old timers have used -- sellers that show up at certain places in Saugus and other areas, folks that buy in bulk and deliver, there used to even be some options in the North End (Salem and Prince at one point, plus others). For most of the sellers, first deliveries came around 9/5 and there is another delivery due this week, but several sellers reported that the shipment was delayed in the Midwest.
Beer and Wine Hobby in Woburn offers most of the selection of M&M in Hartford, but doesn't offer storage. Their prices and selection are on their website, but need to order soon to get some of the deliveries. For non-Lodi grapes and different varietals order from them, also carrying the Italian Must (but not grapes?) that M&M is bringing in. Allow cards. Offer Chilean grapes in April timeframe. They also have a more interesting selection of yeasts and nutrients.
Silvestro Wine Grape off 2nd in Everett. They have the largest selection right now, but have sold out on a couple of things (muscato* which old timers like, grenache, pinot noir). Merlot, Cabernet, Portuguese red (spacing the varietal), Sangiovese, Chardonnay, Mission, Thompson Seedless, Valdepenas, etc. Prices a bit higher, I think they are cash only, but cards might be possibility. Thought I saw something about Italian grapes/must.
Wine Grapes in New England on Beacham: Waiting on Pinot Noir, have grenache, not quite as many grapes as Silvestro but good selection and similar prices. They may take cards. I know they make an effort to stock juices until after Thanksgiving and may do Chilean.
New England Wine Grape (same warehouse as M Cutone): More limited selection, focusing on what Italian old timers buy -- lots of barbera, muscato, some cabernet (might be running low), thompson seedless, sangiovese, not certain about merlot. Excellent prices overall. No cards, cash or check.
Dominic Gandolfo (near Paul W Marks): Just started in the past week, Barbera, Cabernet, Thompson Seedless (no chardonnay, no sangiovese). Expecting shipment on Friday with Merlot, more Cabernet and ..... Good prices, grapes looked nice, smallest selection.
* Muscato (a cross with thompson) as opposed to muscat was what I was told, although I am fuzzy which I saw stamped on crates (I sort of think both).
If anyone knows of local grapes, especially quality lower-brix chardonnay/pinot would be interested to learn more. There also is a lot of Cabernet Franc (which none of the Chelsea folks offer, but B/W hobby has) grown in the southern part of the state and RI.
I decided to omit prices as they may change and I don't have enough data points to give more than my subjective analysis above. For a range of wholesale prices, the USDA does record and post this data. My email is also in my profile if any other interested hounds have more questions.