What is the feasibility and cost to add another GFCI outlet in my bathroom?

I have a GFCI outlet between my sink and toilet. It's the only one in my bathroom. The outlet is taken up by my wall mounted hair dryer and heated toilet seat (yes, only the important things...) Every time I want to plug something in, I have to unplug the hair dryer and the toilet seat cord hangs down the wall and over to the toilet. Would it be feasible to add another GFCI outlet directly below the one I have, close to the floor/baseboard? What would this entail and how much would something like that cost? (Note: I don't intend on have four different things on at once; I just would prefer a dedicated outlet for my heated toilet seat and to avoid unplugging my hair dryer all the time). Thanks!