While I fully realize and expect to get a fraction back from what I've put into the rig, its a rough call to make both financial and emotionally.
Your 80 is just about fully depreciated. Even if you just put a sheet over it and let it sit, it will be worth more tomorrow than it is today.
While you will likely never see all of your money, you will probably get more later. Hang onto it. Once you make the decision to sell you can't undo that, you can always decide later on to sell it if you want to.