I have a similarly sized workplace that I need to heat in winter because I spend 7 to 8 hours a day there working on wood plus I keep completed but not picked up yet furniture, parts, etc here and wood doesn't really pair with sudden temperarture changes... I also want to be comfortable while I work and wear short sleeves for safety purposes. So far installing a pellet stove was the best decision both heat-wise and price-wise because compared to other heating systems it's really THE cheapest one, especially if you buy pellets in bulk for a whole season and have a moisture-controlled place to keep them. The only problem with the stove is that it's so hard to choose one, I remember going through like 10 to 20 pages of different materials, blogs, etc to pick the best one for the least amount of money possible. Ended up with Comfortbilt HP22 and I have no regrets, I've burned 12 tons of fuel already and it works like a charm. Do your own research though, but as a tip consumer report ratings are surprisingly good guides on that, at first I've thought that it's all a corporate shill lol but after reading up they are pretty objective incl. cost of operation and such. As an example this list was quite useful:
https://cozyhousetoday.com/best-pellet-stoves/
Plus search some more and after you've chosen your favourites go and check out reviews on amazon and other sites as some stoves are notorious for certain repeating defects and you can only notice such patterns after reading a dozen reviews.
Overall if you need constant warm temperature stove is a good choice, if you need to use your barn only a few times per week I'd choose another heating system.
P.S.: As a bonus it's very calming to just sit near the stove and look at fire burining after hours of working if you ask me.