I'm a member of a CSA in the wonderful state of Pennsylvania.
I pay around that much. (although in one annual payment for May-Nov)
My farmer has 2 acres of land and about 30-40 members if I recall. So that's the same order of magnitude.
We get more veggies than we can eat. The fridge is always stuffed full of whatever's in season. Lettuces; cukes; peppers; tomatoes; kohlrabi; squash; potatoes; parsnips; etc; etc.
I still sadly need to throw stuff away since we can't eat it all in time. But it's just the fresh stuff and storage veggies. We don't get grains. Corn has a horrible yield density.
They aren't making a killing. I actually had a pair of farmers for the first few years of the CSA, but they decided it wasn't possible to both live off of it, so she went off to do something else.
I did the math a few years ago. It's probably somewhat less than it costs at the grocery store, but it much fresher. You can't compare the taste of tomatoes from a store and something you just picked. (You can pick some of your own stuff also. I'm pretty damn sure he isn't trucking anything in.)
I get to be on a first name basis with my farmer, and I'm helping someone with a local business. He would get pennies on the dollar selling to a store, so it's win-win. And my kids get to see where their food comes from. Anything he has leftover gets sent to a Food Bank.
It would be awesome if I didn't have to drive to pick up the veggies, like these planned towns. Cool idea.