Great work! There are errors of course that you acknowledged but they cancel out of your assumptions are true. I think there is likely an unaccounted for error that would boost the number of pros. Most people on pinside are considered enthusiasts. Enthusiasts spend more because if they're in to pinball enough to be on pinside, they really love the hobby. That means more Le's would be accounted for in pinside collections if I'm correct. Less pros, alot of those end up on routes and in non pinside people's homes since they're cheaper. So, I can't quantify it but i suspect there are more pros than you estimate. Regardless, thanks for sharing