Here is a "vintage" one that sold for $42, but no year listed in the auction:
Doesn't necessarily look vintage to me, with my limited knowledge...
Here is one that looks the same, but not listed as "vintage" that sold for $2.77!
And a "classic" lava lamp that sold for $28:
Is there something I don't know going on here? Just curious, since I'm avidly shopping eBay lately...