The "retail product" was a mistake made by Nightingale Conant. We were totally unaware that they had sub-licensed (quite illegally, too) the product they were marketing for us, to secondary distributors (like Warner/Amazon). We found out after some of you! They subsequently pulled it, after we informed them of their ... whatever.
For those of you sorry about the "commercialization" of GTD, all I can say is, if it weren't, I'd be doing (and would have done) something else. Our contract ran out with Nightingale Conant and we didn't want to re-up, because there's newer versions of the information we want to get out, and frankly, what anyone got on the CD's is similarly packaged for $2000 - not $200, much less $20. Of course you can buy the book for, what? $6.90 (used - amazon). That's pretty mass market, with some pretty complete information.