I think MDs are popular in the states because of events like the Civil War, Gold Rush, abandoned mining settlements and ghost towns that are locations known to produce relics to rare coins and valuable minerals. I believe only the very top shelf, pricey models may have firmware, otherwise those in the $600 and under are pulse induction, BFO, or VLF designs using IC chips and other semis. Yes they seem pricey for what they really are made of. Then again, it's a specialized niche market, R&D depts. need to make up for the large capital investment, and I sometimes wonder if mfgrs. actually think that if a customer is going to find some valuables, the proceeds from them would offset a needless extra cost tacked on just because!