The biggest problem with a "single setting" book is that it is one book that takes profit... and stops that player from buying any other setting books.
I know that I have the LGG, and haven't bought any FR books past the FRCS. If there wasn't the Greyhawk/Realms divide, I dare say I'd have all the FR books.
I buy Eberron books because they are significantly different from the fantasy of FR/Greyhawk, and I like knowing what Wizards are doing. (However, if not for my RPGA games, it's quite likely I'd soon abandon them).
Cheers!
I know that I have the LGG, and haven't bought any FR books past the FRCS. If there wasn't the Greyhawk/Realms divide, I dare say I'd have all the FR books.
I buy Eberron books because they are significantly different from the fantasy of FR/Greyhawk, and I like knowing what Wizards are doing. (However, if not for my RPGA games, it's quite likely I'd soon abandon them).
Cheers!