There is a double cover X-men 100 on ebay right now.  It is also a 30 cent variant.  Here is the link:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=380072861201

We have discussed this before, but this particular book got me thinking about "variant" variants again.  We all know how rare most bronze variants are compared to their normal counterparts, and this just kicks up the rarity exponentially.  We have seen double cover variants before like the CGC graded Marvel Feature 4 with the awesome Red Sonja cover, and I believe Cosmic Spider Man has a double cover 35 cent variant, but these books are almost non-existent.  Add to that, the fact that X-men 100 is as close to a key as there is in the 30 cent variant run, and you have a potential monster, price-wise, in the making.

Other "variant" variants we have seen besides double covers are printing defects, error covers, and color variations.  Doctor Strange 14 has both orange and yellow starburst 30 cent variant editions.  Captain America 212 has a version that is missing the words "Marvel Comics Group" from the banner of some 35 cent variant editions.  The STLcomics gallery of Modern Discount Marvels also showcase two books, X-men 423 and Avengers 77, that have conflicting cover prices on the cover of the newsstand editions.

Whatever may interest you about variants, you would have to admit that a variant of a variant is another stretch into territory not easily accomplished by any collector.

Please stop by the forum at STLComics and let us know of any variants of variants you may have, or have seen.  We are interested in them all.

-ShieldAgent