Going back to the OP for a moment, I appreciate your expanding on your previously-expounded thesis. I am generally convinced by your arguments that...
A) By comparison with Gygax and the Blumes, Williams was definitely more restrained in self-dealing.
B) In a closely-held company it's really not a big deal in the first place.
I will still maintain my quibble that IMO you're overselling and overestimating the value of the Buck Rogers franchise.
The TV show got
two seasons ending in 1981. The
1988 board game wasn't based on the show, and had a completely different aesthetic and concept, so tying the two together purely on the character name is a bit of a stretch, IMO, and using the show as evidence of market demand for the board game similarly dubious.
As far as "show me the receipts" goes we know that the board game was a big flop, and that when they tried again two years later with an RPG that was a big flop too, though it still got
at least a dozen supplements and ten novels. Which my recollection is didn't do well either, but maybe
@JLowder can recall details, if we're lucky.
We'd need internal numbers to express any kind of
definitive judgement on whether it was a market-rate transaction, but I think the data we have does generally support the position that the whole idea was kind of dubious from the start and more than dubious later, shoveling good money after bad.