Here was his response when I asked him if he knew they usually go for $10-15 each:
Dear eyeam.gawd,
An excellent copy of a single module in this series usually markets for
$20-$25 at the vendor's booth of any given gaming convention in the
country. Most modules for sale at these booths are in marginal condition
at best (representing a total waste of money), and I have never seen a
single vendor offer the complete series. I know this because I have been
to many of these conventions myself, precisely for the purpose of
acquiring this particular series, and it took me quite some time to
assemble what you see.
So, assuming:
(a.) you have the means to travel around the country at one or more
gaming conventions of your choice so you can personally sort through,
inspect, and purchase only the best quality modules available,
and
(b.) you could actuallY FIND all of these in good condition in the vendors
area of one or more gaming conventions,
THEN you'd have to pay roughly $200 for the lot, plus travel expenses and
lodging. But I can guarantee you you're not going to be able to put
this set together buying from any single vendor, or even from many
different vendors at any single gaming convention in the world. If you
know of a vendor or a place on the internet that offers such a set, please
send me the link, and I will buy it.

The value of this set lies in its completeness. There is tremendous
value in the time and effort it took to assemble it, alone. It doesn't
have to sell now. All it has to do is sit and grow more valuable over
time, which is sure to happen no matter who owns it.
Thanks for the comment.
- JediShrike
Gee, lucky for me I have all printings of each of the monochromes. I should just sell them and buy a Ferarri.
If you hit a Rowsdower, you get to keep it.