I've played sites for £20 and had a bad time, and played sites for £35 - £40 and had an outstanding time.
The opposite is also true.
Every time you pay your fee to play you're rolling the dice. There are so many variables as to what will make your day good value for your money; site size, development, layout, rules, marshaling, weather etc....
But frankly, the thing I feel makes or breaks ANY game day, no matter the site, are the players.
All it takes is a few dickheads to flip a day and make me regret handing over my hard earned cash.