We could debate this all day. In short, personally I don’t think it’s an unreasonable charge if I want to park conveniently and ride purpose built trails somewhere with a washroom and a cafe. YMMV etc.

My mileage certainly does vary. 😁 I’m lucky enough to be surrounded by Welsh trail centres (all of the southern ones within an hours drive). I also spend a lot of time working away, which means I get to ride a lot of places. To give you some reference points, I rode at Newcastleton and Glentress last week. No charge for parking at the first, £5 all day at Glentress iirc. Bargain for such good trails. (Glentress – Newcastleton was rubbish.)  Off the top of my head, in the last few months I’ve ridden Swinley, Whinlatter, Thetford, Sherwood Pines, Cannock, FoD. None of them charge more than £5, iirc. The problem that I’d have with £9 is that, almost without exception, the English trail centres are dire. I won’t  justify £5 for somewhere like Sherwood so Dalby would have to be the exception to justify that charge – or offer free cake. 😂