What kind of bass this is doesn't matter. It's an object with value, which is all that matters. When I sold cars for a living, I once traded for a rifle. This kind of deal is easy enough...here's what you do:
- Go to a music shop and take full information about the bass to them. Perferably, take the bass to them so they can inspect it.
- Get a firm quote on what they will buy it for. They will give you a wholesale quote that's about 50% of retail. If you cannot get the actual bass for them to inspect, reduce that quote by $50-$100.
- Offer the car buyer the resulting amount against your car. (Note addendum below)
- If he takes it, make the deal, go straight to the music shop and sell it to them.
Here's how you keep from insulting the buyer...you have an asking price for the car, right? And you have a separate, lower price that you're willing to accept, right? So you take the wholesale quote from the music store, add the amount you're willing to reduce the car's price, and offer that amount to the bass owner.
Example:
Let's say the car is advertised at $1000 and you're willing to take $900. You have $100 to play with. If the bass will sell for $1200, then let's say the music store's offer (wholesale) is $600. You offer the bass owner $600 + $100 = $700 for his bass.
That's how trade-ins work, and it's done thousands of times every day. It doesn't matter what you're trading.
