If you can go check out a few different detectors in person, test them out.
You also need to figure out what type of hunting you want to do with it, coin & jewelry, relics, gold, etc., most detectors will do but some are better at certain things than others. Also will you be hunting mostly parks, fields, schools, or beaches? The more info you have as to what you want and where you want to hunt will help you choose one that suit your needs. Also where you live may have highly mineralized soil. But most of all what ever you choose have fun.
You may want to check out the videos here on the subject and previous threads that people have ask the same question and see what answers were given.
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