So you're saying that Holmbush invented pump days? I have been on at Niall for over a year to do a pump event.
Of course the pricing is going to be similar if you think about it. Our regular walkon is £60 with a box of paint for non UKPSF members, if we provide half the amount of paint then the price will reflect that. If we price it too high no one will come, too cheap and the day will lose money.
I don't know about 5 sites doing a pump day, there is Holmbush, us and Sabotage as far as I can tell. Geographically we are far enough apart. Team GBH are the only people who go to walkons at both sites as far as I know.
Have you considered the other side of the argument, that more interest will be created in pump play by having more events? This section of the forum has got busier recently with various people looking at buying their own pump. I even get PMs about buying a Sterling.