I think metal detecting is worth every penny invested in a detector.
First, don't get a really expensive detector. I own a Garrett Ace 250. It is great for finding coins and small (or large!) metal objects. By shooting for coins, you get a lot of practice. You will learn the basic motion when you use any detector. You will also learn the basics of reading the output.
If you enjoy that and really want to try to find gold nuggets, then you will have to invest in a more expensive model. I don't think the 250 will help you find gold nuggets so well. It just doesn't discriminate well enough unless you found a humongous gold nugget. My friends in a gold hunting club think White is a great brand. I am not really qualified to advise on that, but you can get the low down on the internet or a prospecting/mining store.
If you enjoy being outdoors and finding coins (lots of pennies) and the other interesting things like old nails, spurs, bridles, buckles, rings, etc, then you should move up. If getting better at using the detector bores you, then I would suspect you may not have so much fun using a higher priced instrument to try and find nuggets. Gold is hard to find; that's why it is so expensive! But, it is out there - I have found 2 nuggets by accident when washing, not with my detector. The most valuable thing I have found with my detector is a silver ring and quarters. I think it is great fun.
If all you are interested in is the value of objects, the time you spend hunting may not seem worth it - a minimum wage job may pay more. However, there are all kinds of things people over the ages have dropped, and finding one of those things could help you retire very early.
See if you get the fever with a cheaper model metal detector. The Ace 250 cost me around $250. The price may have gone up some recently, but I think it is a great model. If you get the fever, you need to invest some more money (which you will be happy to do). Good luck.