Being a part time artist, I can say the pricing structure depends on the category of artwork and the artist's background. Not to forget if you are dealing with similar structure as subscription boxes it is imperative to know what is your central product concept.
Installation and procurement costs need to be addressed separately. The business model can address different commercial aspect to develop long term relationships.

As far as artists are concerned, there are specific measurement of the art piece and standard pricing for first sale. Now with NFT there are avenues of resell percentage that lands to the artists. The current trends need to be addressed. Ownership can be addressed with the type of contract that is being modeled.