I have a neighbor who wants to sell me two Bounty Hunter "Big Bud" NT metal detectors SN 1541. They are almost 25 yrs. old and they have the paperwork books etc. About 400.00 (ea.?) new back then VLF technology. These actually have the meter showing what you have found - new technology back then I think. Does anyone know if there is any value to these, how well they work, or what they might be worth?