Coins like this are surprisingly common finds in England. In exceptional condition it would fetch a few hundred pounds retail from a coin dealer but this one is not in great condition. You can find similar for £20 on eBay.
I have one coin of Charles I from 1643 that is exceptional that I would like to get a professional valuation on. The dream would be to find a hoard. Of course you have to declare it to the coroner and wait a very long time to receive 50% of a not-too-generous estimate. The other 50% goes to the landowner.
All my finds have come from within half a mile of my house. Discovering the history is the most rewarding part for me.