Depends what equipment you get. Can be expensive but pays for itself ironically if you find something really valuable. Look on Amazon and see if they do a beginners kit for a cheaper price. No point wasting a chunk of cash on a new investment if you get bored of it two months down the road.
A good walk ruined by looking at the ground all day! Seriously there must be some ‘hoards’ still awaiting discovery somewhere. Fame and wealth awaits! Couldn’t believe the recent case where finders of a hoard didn’t declare it and ended up in prison - they could have been comfortable financially if they’d gone through the official channels, and our history would be richer for it.
My old neighbour used to do it. He would visit local outdoor events, mostly travelling fairgrounds, the day after they left and hunt for coins dropped. Not sure if he ever recouped the cost of the equipment but he always took great delight in showing me a big jar full of coins that he found.