Just How Rare is ABC on Gold Vinyl?

This eBay auction makes an interesting claim about the gold vinyl ABC promo with the original printed sleeve:

ABC GOLD VINYL PROMO w/CUSTOM SLEEVE~Michael Jackson 5
ONLY 150 PRODUCED ~ ONLY 26 IN EXISTENCE WORLDWIDE!!!!!

Really?? In my life as J5 collector, I have purchased two of these with the original printed sleeve for reasonable prices ( under $50), and I see it come up for sale on eBay several times a year -- including the custom sleeve that makes this item rare in the first place. In fact, there are currently two for sale on eBay right now.

It's not nearly so rare as, say, Rappin' with the Jackson Five or the Canadian promo single for I Hear a Symphony, which only come up for auction once in a blue moon. Not to mention the extremely rare U.S. promo for the canceled single "Boogie" with a picture sleeve, or the Brazilian pressing of Jackie's only known Motown single, "Thanks to You." Both of these are so rare I've never even seen either of them for sale, and have only seen a photocopy of each one from other collectors. I could actually believe that there are only 26 of them in existence.

And that's another thing. How did this seller ever arrive at the number 26? Maybe it was based on a count of the number that have been on eBay in the past year.