My understanding of when the event was moved to Vegas is that there was no cash from Pontiac involved. Fred Simmonds who ran the Pontiac program was a BIG Pro Stock advocate and strongly encoraged the GM teams to participate. He also contributed to the promotion of the event. I believe the trade off was some free test days for the teams, and they put on a show so the track could recoup the cost via ticket sales. Kind of like the West Palm Nitro test/event last week.
I don't know what the Houston arrangement was but would guess it was about the same.
I believe it ended up being a losing proposition or maybe a break even at best for the track, and most of the teams would really rather test than race and it just went away. One thing I know for sure, if it had been a profitable deal for the teams and the track, they would still be doing it somewhere.
Just for the record, I'm not stating this as gospel, but I do have pretty close ties to LVMS and this is how I believe it went down,
Alan