Don buying a metal detector is a personal thing like getting a rifle or a caliber for a specific purpose. If you just want something that will beep or buzz when you swing over metal then the $29.95 Walmart detector will do this. If your interested in finding Gold then get a detector that was designed especially for gold. Treasure hunting on beaches or ball parks under bleachers are anther thing.
In your area you will cross a lot of hot rocks and barbwire horse shoe nails you will get very tired spending a lot of time finding those sounds. You should dig up every single till you understand your detectors language. I can tell if I pass over a piece of wire or a hot rock but not a bullet, shell case or pop can from gold
There are several good detectors out there for Gold. The Garrett AtX I been reading is proving out good. Fisher and white are also a descent detectors.
I use a Minelab and it has done well for me, but it is heavy and when you swing it all day you will start looking for that tether cord that they packed with it

But I have #5 or #6 lead shot 6" down using it. The detectors I mentioned for gold are not cheap.
Go on this web site and page down to the detecting and do some reading by the people that use them.
http://www.goldprospectors.org/Community/Forum/aff/6
http://www.detectorprospector.com/forum/...-gpx-5000/
Kurt