WIY, I’ve never heard of people selling fake organic food. It might occasionally happen, but there’s no way it happens on a large scale. Organic agriculture is practiced by thousands of farms, some of them very small, but it’s big business — and some of these California farms are huge corporations. Corporations like that don’t mess around when it comes to counterfeit goods. If people were selling fake organics, the industry wouldn’t stand for it for a minute.
If fraud were really an issue, the best place to go would probably be a health food-oriented food co-op, because the people running the place really believe in organics. At the (out of town) place I shop, I think they actually subsidize the prices of organic produce to make it less expensive than it would be otherwise, to encourage people to buy produce rather than processed food.
Sorry — I’m not a good source of information on how to grow apple trees in Brooklyn. I’m sure there are nurseries there with knowledgeable people. It would probably take a few years, unless you bought a pretty mature tree. You would have to make sure you pick the apples so there isn’t a big mess of rotting apples piling up under the tree (as happens with apple trees planted outside of stores where I live.)
If you have the time, though, and Brooklyn’s climate will allow it, that would be a fun thing to do. I’d like to have my own apple or pear trees one day myself. I’ve had my own community garden plot for the last couple years, which is a nice way to grow a lot of cheap vegetables, making my family eat more veggies than we otherwise would.