Regarding metal detectors - indeed you do get what you pay for, but saying that I have a modest Garrett ACE 250, Have found loads of coins, traps when i lose them, but helps if you have a rough idea of where you think it is.
Finding traps can be a slow old game, depends what else may be burried where you a searching, you can filter out items your not looking for, and I will familiarise myself with the noise the detector makes when hovering over a trap before searching, that way you will be in tune with what your searching for.
Sometimes I will metal detect mole hills, can find buried t