To echo kja (and trying not to be negative) forget selling at marts or to local butchers with kunekune or meishan.
Neither are exactly what commercial buyers want and tbh I don't think I could drop off a load of pigs and not know what happened to them
although most of my pigs have short lives, I want that to be with someone who has a half idea of what they're doing and keep them in good conditions until they go to slaughter. It all depends on your moral barometer.
Kunekune pork is fabulous (don't think of it as 'just' a sausage pig) - but direct selling to consumers, whether as pork or on a grow your own scheme is the best way to ensure you make a small profit
Meishan's, I believe, are more of a lard breed - though often they are used in commercial hybrid breeds as they're prolific mothers and very milky - I haven't tasted their pork but would imagine it's similar to kk - slower growing, rich and tasty meat. You might have some work to do in terms of marketing - think hard to find your niche market and go for it.
Keeping pigs year round is a big commitment (especially if you're in an area where winters are wet and they need housed for part of the year) if you only have a couple of acres and they're out all year round you will find that your fields are soon just mud - being able to bring them in REALLY helps with land management.
What works for one person in one place might not work for another - unfortunately the only way to know if it's going to work is to try it
Good luck with your plans and please feel free to show us photos of your wrinkly squidgy meishan piglets