G'day Samclab, i use the Whites MXT  price on that in Aus dollars is $2,600.00 but if you look around for a second hand one it does not have to be the mxt, you can find a good one for around $700.00.  Just stick to the well known makes such as Whites,Minelab,Garret and fisher you can't go wrong. You must have a detector dealer in your town or nearby,give him a call and explain it to him what you want and he will be able to put you on the right track.   The secret to finding coins is to search out the places where people gather in numbers,then you will find coins easily. Raoul