So I found a fairly large mounted doe in a storage unit (side note I buy and sell storage units) and I was wondering if someone could please tell me if there is somewhere I can sell it or maybe what it's worth?

try craigslist.
doubt anyone would be willing to pay much for it though. really depends on how good a job the t-man did on the mount. hard to tell from pics you posted. you can get your own mounted for 3 to 5 hundred . so if your lucky, I'D GUESS MAYBE, MAYBE A HUNDRED BUCKS. most folks want a buck, or at least a deer they shot themselves and really, unless it was an exceptional buck , there probably wouldn't be a lot of interest.

I could be wrong.good luck and let us know how you do

Not too many people are going to be willing to pay much for a doe head.

Take it to some local restaurants that have that kind of theme. Or like what was said above. Craisglist or E bay

Donate it to the science dept at the local high school and take it as a tax deduction. Look on some taxidermist websites and see what the going rate to mount one is and put a 60% value on it for tax purposes.