NEC Classic Motor Show:
I guess we have to accept the costs for what they are, and make our own decisions on whether to attend.
The parking charge is set by (and paid to) the NEC, rather than the show organisers. Some shows (eg the Motorhome and Caravan show, which I attend) have "free" parking, but that will simply mean that the organisers have paid the NEC. They can afford to do that, because the occupants of each stand - eg the motorhome manufacturers - have paid the organisers fairly huge fees to have a stand. With the Classic Motor Show, the organisers charge the clubs etc absolutely nothing to have a stand.
So, is the entry fee of twenty-odd quid too dear? We'd all love to pay less, of course, but the practical answer has to be "obviously not": all eleven halls were packed, but walkable. The organisers will set the price at a level where the place is buzzing, but not too full to enjoy, or be unsafe. Clearly, they were spot on!
I was lucky enough to get in free, but could spend little time off-stand to see the rest of the show, and soon decided to have a day next year when I'm there to do my own looking around. Even if it costs me!