I highly doubt a SPA management team worries about making profit on baby oil. They would be worried about rent, by-laws, landlords, promotion, customers, scheduling, visas etc.
Baby oil can't be too high on the list of priorities. Funny thing, I had one MPA ask me to buy her some sex lube because she liked the brand I brought into the spa. When we had FS, she said it felt nice (the lube, not my dick I suppose). I left my bottle of lube for her and told her to enjoy it.