There is a guy here who paints very realistic/very soothing ocean murals on peoples walls.

He charges $900 per wall and has a steady business with no marketing expenditure other than WOM.

If your paintings are that good and I don't doubt they are, $200 is way too low for specialised mural work

If you went to a muralist, a good one and wanted a special job done, just like you do, it'd be more than $200 especially on the ceiling.

Your work is too good and too specialised to be too cheap.

Just my 2 cents worth.

As for the Motel angle, offer them the straight $900 or what ever you put it up to deal, don't complicate your business by offering a profit split or share.

Practically all business people price what they do and what they have too low.

Get that price up!!

MW