If you read the wikipedia page http://en.wikipedia.org/wiki/United_Club it says you can buy access to United Club, but doesn't say that about the first class lounge. In fact it says:

"the access rules are significantly more restrictive than for United Club. Access to Global First Lounges is generally restricted to United Global First passengers, Star Alliance First Class customers, and Global Services passengers confirmed in Business Class."

In the first class lounge you get free food and drink including alcohol. If you could really get in for $50 a day, you could easily eat and drink that much worth.

No need to pay $50 a day, just buy a fully-flexible first class ticket and keep re-scheduling it:

http://timesofindia.indiatimes.com/world/mad-mad-world/Chine...

Or just get an American Express card (Platinum, ideally - no additional fees) and net access to the Centurion lounge and all Delta lounges (when flying Delta).

The Centurion lounge is second-to-none domestically, and the Delta lounges aren't half-bad when it comes to the free booze (some are self-serve - Jack Daniels, Grey Goose, etc.)

United's clubs are a joke comparatively.

And they haven't reduced the fee even while losing Continental lounges when it was bought by United.

For my money, the Citi AAdvantage Executive card is a better similar card, because it now gives you access to all AA and USAirways lounges. While you're right that in my experience the Delta lounges are better (the only amex lounge I've been to is at mccarran), what matters most to me is a lounge in the cities i connect thru.

The Citi card is the same AF as the Amex Plat but Plat has policy of never waiving first year AF and Citi often has a promotion doing just that (or a portion of).

GS is a special invite status reserved for celebrities and high ranking politicians. My assumption is that they need that space so that they can load the person from the tarmac or have them check out of the airport. Thats speculation, but those individuals do have different needs from an airline. [Also onboarding needs as well as that they don't enter from the jetway]