I love metal detecting. I used to have a metal detector that I bought from Walmart and would go out from time to time. The problem I had was there were so many other people in my area doing the same thing that most of the places I went to were pretty much detected out.
One time I wanted to go detecting at a historic school that had been closed up for years. I traced the owners of the property and contacted them about it. They gave me permission and I started working the property. I found nothing of interest. As I was working, a group of kids came up to see what I was doing. During our conversation they told me that they had watched a group of people detecting on this property some time before me, and said that they had found lots of large old coins! I knew then that there was probably nothing left to find there, especially with my cheap detector.
But, if you can find the right place you can come away with some really interesting and perhaps valuable things.