This game does not have a concept of used ships. You can use a ship for a year, repackage and sell it as new. If you don’t fly Asteros any more, you can sell it for whatever you like just to get some ISK out of it. If it’s below market or production price, at least you’ll get ISK faster.
Not everyone is buying resonators on the market, or even simple minerals for that matter. Direct bulk trade and contact with suppliers usually yield much lower prices. If you are buying materials on the market, you are immediately in disadvantage.