Hmmm, this one is a pity.
On the one hand the farmer is being helpful and not ripping people off for parking. £3 doesn’t sound like a lot for parking near a beach but he isn’t doing it for charity either. I suspect he rakes in quite a nice earner for this.
On the other hand if he gets a bill for £1-2k (It soon mounts up) he may not look on it anymore as easy money. Would be surprised if he has relevant insurance for doing this tbh.
My guess is you will get your estimate, he will pap himself at the amount and refuse to pay. You will chase for ages and then go through your own insurance and get it sorted. You will insist to your own insurance that they chase the farmer for it and he will state that you parked in the wrong field. Your insurance wont be bothered to chase and it will be very stressfull for you.
Get your estimate carried out quick smart. Send it to the farmer and follow it up quickly. If he is straight forward then everything gets done quickly etc. If he messes around then don’t waste time on hime. Get your insurance involved and move on quickly.
Too much time wasted in life worrying about things other people do and for things you have paid insurance for