Welcome to the forum
So buyer wants you to set the asking price for a vehicle that is not for sale?
Not the way it works.
Up to him to give you a bid, then you can either take it or set an asking price, if it is indeed for sale.
If you need a small pickup then you should look at what the cost is to replace it, not specific to the year or model, just a small pickup that suits your needs, or say "it's not for sale", at that price.
Ultimately the buyer always sets the value for something that is for sale.
Asking price is just that, asking, not getting, so not a true value until is it sold, then the value is established.
Looking at "For Sale" ads for similar products/trucks gives you an idea of what sellers "think" their product is worth, but it is just an asking price, not a value.