The shop system seem a bit weird, why would a dumbbell has a higher upkeep than a book? It is just a piece of iron/lead, the only maintenance it need may be some paint? And how is keeping a desk more expensive than a butler?
I think the items from the shop, like the books, dumbbell and desks, should have a higher price, and once you buy it, you have it forever. And servants should count separately from inanimate object, and take wages as long as you hire them like it is now.