Usa
That number became more difficult to determine since the news came out that Phoenix Arcade/BAA might make repros for around $200.
But there's been no update since March:
http://rgparchive-removed.com/rgpforum/showthread.php?t=389899
Originals will always be worth more--but the one you mentioned has fade. You can get an overlay from LSOG to deal with the fade if you want it perfect, but there's an extra $50 expense:
http://littleshopofgames.com/Games/ww.html
The value is in the foil (most have bubbles).
It's a bit of a risky moment for buyers and sellers--but since Phoenix/Bay Area are involved, sounds like it's most likely a question of when, not if...but you never know. 
Present these facts and make a lowball offer you're comfortable with if repros are in fact produced.
