Delta normally charges $50 for a single visit pass, something that I’d almost never consider to be ‘worth it.’
Through the end of the year, though, they will sell you (4) passes for $99. That’s about $25 a pass, or half off the regular price.
You can only purchase the passes in person at a club, and you have to mention that you want the special offer (I guess if you just ask for 4 passes they’ll instinctively want to charge you $200 — but if you know the secret handshake you get it for half that).
There’s no way to make the purchases online. But you can do it at any Delta Skyclub, you don’t need to be using the club that day in order to buy the passes and you don’t need to be a member to buy the passes. They’ll be valid for a year and won’t have names on them, they can be used by anyone.
Two years ago they made a similar — though better — offer of five passes for $99, about $20 apiece.
Potentially good for the occasional lounge visitor who will be getting less value out of the Skyguide Executive Privilege Club in the coming year.