I dont know how much my dunlop tire is worth.?

I have a dunlop 245/50zr16 sport 5000 Tire...everyone tells me theyre crazy and really expensive and I had a set on my 93 z28 camaro, anyway I have a spare tire that I wanna sell...it's brand new never used, how much can I get for it do you think?|||If its never been used and the date code is over 3 or 4 years old its probably bad and it could seperate at freeway speeds.