How does hiring a wedding stylist actually work?

So my fiance and I know absolutely nothing about wedding stylists. For example, how much does one typically cost? In all of my research so far, I have been quoted any amount from $900-$5000 and really don't know what is normal. Also, are the prices of packages generally the cost of the entire service? For example, if I've been quoted $2500, is that how much I will pay for the entire styling, or will I have to pay on top of that for supplies? I'm sorry if this is a stupid question, I just honestly don't know and am not sure how much to budget for! Thank you!