If you post a picture of it, you will get more accurate answers. In general, you should search first and ask a high price, and then until you reach the right price. Asking about the price of a commodity you own will result in an evaluation of it at less than its fair price.
Is it worth putting it into a crypto exchange and earn interest on that, or should I keep it closed?
It is better and safer to convert your money to good POS cryptocurrency where you can get a free APY return although I think the return (in dollars) generated from Bitcoin is high and appropriate.