I am 75 years young and have been metal detecting, land, beach & underwater for over 55 years now. I cannot even begin to explain how much I love it. The simple answer is "The Thrill Of The Hunt". I have found thousands of items over the years. About 70% of what I have found is junk, trash, pull taps, etc. Yuk!!! However, I have found, literally thousands of dollars in Coins & Jeweler as well. For the most part, my very best finds have been on sandy beaches, mostly in Florida and the lake beaches in the Mid-West, Great Lakes and the unlimited number of inland lakes with beaches. The 2nd best is kind of a tie (Land) Public Parks, School Grounds, Forest Preserves, Corn Fields and so on. The 3rd in line, but usually offering high valve targets, is in the water, at public beaches. The least productive, but one that can be extremely rewarding, is gold nugget hunting.
I have owned at least 20 different detectors over the years, from $100 units to $1500 units. Over the last 6 or 7 years, I sold off all of my older equipment and settled in with just two units. One a Bounty Hunter for hunting Public Parks, School Yards, etc. and the other for a bit more serious hunting in the desert and beaches, a Tesoro Outlaw. Links are below for the units, I now have. I can tell you with extreme confidence that you do not have to spend more than a $100 to $150 for a good, competent detector for hunting Parks, School Yards & Etc.
Tesoro Outlaw with 3 Coils Metal Detector - Kellyco
Bounty Hunter Tracker IV Metal Detector - Kellyco
Pm me if you have any questions I can help you with.