well i guess it depends on details and if they will be dresses, pants etc.
does she sell them on etsy or the like?
i would think between 3 and 5.
i don't own any msdolls, but when i was buying for the doll swap last year i did alot of research and the clothes i bought ranged from 10 to 15$ each. @.@ alot more than what i was used to.
(hope my partner can use them) but it really depends on if she's going to do lace or buckles or eyelets details etc. that might even put it towards the 20$ range. those things can be a pain in the bootle!