Veg Trucks - YES!!! Prices are not only cheaper than in most markets but the produce is fresh and seasonal. We've had two different trucks come by the yard twice a week for several years - Sammy and Mr. Gaye. That is my first choice in buying fruit and veg.
You also do not necessarily have to go to a big supermarket - the little stores such as M&L and Wise Choice may have a more limited selection of stuff but their prices are about the same.
Negril has three big supermarkets now - Value Master, which is better stocked with local products but not so much imports/American Products - the "Green Store" in my opinion has the best produce and the largest selection of cheese and ingredients for Indian and Asian cooking. The produce prices are the same as say HiLo and Value Master but the rest of the stuff is a bit more expensive.
HiLo is the go to supermarket for tourists and a lot of Expats so they carry a very large and varied selection of imported American and Canadian goods. I find them to be a bit more expensive than Value Master.
Chicken has become expensive and when buying make sure you look carefully at the date the chicken was packaged. As far a fish, there's a fish market diagonally across from Canoe where I get my fish - again, very reasonably priced and good combo of fresh and frozen items. I don't like to buy frozen fish in general but I know these guys flash freeze right away and once thawed it is very fresh.
Interesting observations here about letting people "in". I understand it as well - I've thrown my trust in people only to have it smack me in the face. But more often I have made many friends who are loving and generous and community minded and are eager to help whenever they can. By volunteering at the school or in the soup kitchen or where ever you'll meet those types of wonderful people. I feel it is important to establish community where ever you go in this world and I encourage that for you!
I think in RGonda's story the lady was probably "behaving badly" in general, not just going to the Soup Kitchen.
"In my experience, the tourists who are perceived to have money are granted some lenience on their bad behavior but are often marked for cons and scams by those with bad intentions as well. "
That's not been my experience. No one will ever say anything to a tourist, especially one "behaving badly" but throwing money around to their face. But once they are gone they become somewhat infamous - if someone attaches a "crazy" before your name you know that you've lost respect in the community. Medi, I don't know you but from what I've read you are a respectable and kind person so I don't believe you are in any danger of that. But I've listened to Jamaicans chat not only about tourists but long-term visitors and residents...not dangerous chat but definitely not respectful.
As far as the woman who's story I heard almost as soon as I got off the plane - well, other than eating at the soup kitchen, yes, her behavior was wild and she got a reputation for sure. The Negril grapevine moves very quickly with facts often turned inside out - especially during slow season. And its not just the Jamaicans - there's a certain "popular" expat woman in town who loves nothing more than to make brief observations and then immediately gossip and trash the integrity of certain people whether she knows them or not.