"At an FT get together, I was regaled with a story from another FTer about how his Black Am Ex got him top tier with every FF club out there - and it only cost him $150,000 a year of spending on other stuff."

Let's cut the hyperbole. As great as it may be, the Amex Black does not get you top tier on every FF program out there. As noted below, it is only a handful of US carriers, and often just to the mid-tier level.

As for paying for Priority Club, I agree Gold is of little or no value, so $50 is really a waste. And the Six Continents Club offer for Platinum status will cost a non-member $150, since that is the new sign-up cost for that program. The PC Plat is a new offering and may not be included in the basic membership tier after this year.

Interestingly, PC requires one of the higher accumulation of nights before granting its top tier found among hotel programs. Starwood now seems to be the easiest program in which to get top tier Platinum status.