If you're trying to make a living from the app (I don't think the post is too clear), I found my only success with a unity plugin was to release it for cheap/free to build users and charge for new features at freelance rates.

People who REALLY need features are businesses or projects who have money and usually a deadline.

At one point I was making maybe 1k/month from sales and 3k in feature inplementations. (Helps that I also freelance so not a big jump in terms of my day to day flow) Not crazy, but I was also freelancing at the same time.

The real time drag is supporting the free users. The people paying for features and using the plugin commercially were a lot more competent.

TLDR: build free reputation & word of mouth, then go B2B. Obviously depends on the target audience