I think this would be a fun thing, and for me the possible difficulty of implementing it isn't really what stood out here. My main issue and worry is the pricing of bookshelves - right now they're decorative so they don't cost much, but using them as storage would raise the price massively. An alternative to that could be possibly using a seperate textured block to be the bookcase - bookshelf is decorative, and bookcase is storage?
But yeah, the pricing is my main worry here.