How Rare Are Signed Lloyd Waner Perez Steele Cards?

[tinkereversandme]

I collect signed Perez Steele cards and I have always wondered how rare signed Lloyd Waners were. Clean Sweep says the following about the one in their current auction:

As with the Paige, an almost mythic rarity needed by virtually all collectors of signed Perez Steele cards. Lloyd Little Poison Waner passed away in 1982, long before the era of the autograph show and before Perez Steele cards caught on among autograph collectors. The offered card came from a very early set and has been in a closet for almost 25 years and was unknown to the hobby until now. Waner signed this in bold black sharpie - he began with one pen and finished with another (as determined by James Spence by examination under magnification). This is quite simply a superb example of one of the rarest signed cards in existence. This is only the second one we have ever handled, and we have not seen any other authentic examples in years. JSA LOA.

Now I have trouble paying $3,000+ for a $15 autograph, but how rare are they in "authentic" form? Experts, how many do you estimate exist?