My initial reaction was, of course they should finish your hair for you!
But upon reflection I realized I've only had two hairstylists who could successfully diffuse & style mine curly, and the others would try to blow it straight with varying measures of success; and even the ones who could dry it curly it still looked better if I went home and did it myself, so I guess no it really doesn't matter.
But if they don't do it I do think the price should be different; Tiffany who I go to now has 3 or 4 different prices for how much you want 'finished' beyond just the dry haircut, and this makes sense to me.
2c / C / iii (FIA)
Med-Coarse, LowPorosity, NormalElast (LCLF)
Wash: DevaCare Low Poo
Detangle & Rinseout: Walgreens or Sally's Conditioning Balm (always)
Leave-in: DevaCare OneC (budget choice is GFTN)
Style: ReCoil & DevaCare Arc Angel (budget choices are HESMU or Got2BSpikedUp)