There are ways to get them... along with the 'illegal' kind on IRC and Kazaa.
Not that I endorse the illegal kind, in fact, it ticks me off, however, like you I like to capture the 'legal' releases and to my knowledge it's not illegal to own these even if they were initially put out on a private list.
(I'm NOT talking about scans of books or the pdfs that people sell online.. I'm talking about the 'web enhanced' products that
WoTC puts out under the RPGA umbrella).
Anyway, I have a theory that you can find anything on IRC if you know where to look. Kazaa should work too.
I won't put IRC info here but you can email me if you want help or hints about where to go. (although it's the dark-soft-white underbelly of the internet so you need to tread carefully)