If you really wanna find out how much is worth, list it for $25k obo. (Maybe go higher, these days that might be too low to grab attention)
Priced properly, your listing will get plenty of attention! 2-4 pages of comments all over the spectrum (including hits like "Does it come with the crack pipe?" or "I've had offers of $25k for *mine* but I won't sell")
By the time the dust settles, you'll likely have received a few real offers. Then you can happily choose your buyer and take your $15k +/- to the bank!
But *please* share the actual selling price at the end of the fiasco. There's been way too many moon-shot sales lately that apparently went through, but without a final selling price disclosed from seller...