I agree with all previous comments, but I feel that the real is in knowing how to handle and interpret the signals of the device you of your choice, no matter the brand, or what you charge, that would serve you spend 45,000.00 on a artifact that can not or is very hard to learn their use, or have to take a course at NASA to learn to use such expensive apparatus, What I recommend and that anyone can give is the experience that you buy from the field, and well you know your partner are actually mail your eyes on the ground, experience, expertise, experience ........... and that's just the years you get it if you want to succeed, regardless of the field to your going to hunt, remember every moment and think, for now I am having experience, and achieve success to recover a treasure, with 100 or 200 years underground, nesesariamenta not have to be 20 to 30 feet deep, I will asking you is worth more monetarily speaking historical or prefer to find 60 gold coins at a depth of 3 feet, or a cartwheel at a depth of 30 feet, the desicion is yours, but I insist EXPERIENCE ... all is said