Pricing?

How do you figure how to price your toy? I've never been one to be able to price accordingly but if the toy is worth it to someone, I want to get what it's worth. (I guess this could also be like other physical items)

May main question I suppose is how much would a Medium size Seadragon go for? Not the new one but.. the old retired/legacy one? Same with say... a small crackers?

I'm reaching out because I do have these two to sell but I honestly have 0 idea what they would be worth.