The following attempts to summarize what we've learned regarding the print runs of various D&D items.  Where applicable, we'll note the source of the info.
 

From a Wizards of the Coast employee, who wishes to remain anonymous (thanks to Ralf Toth for forwarding this information):

For stuff before 1980, the record keeping was abominable.  There is a little data on the core books, but nothing on the smaller products, like adventures.  We pretty much had to guess, based on revenues and release schedules....

I don't have the specific data handy right now, but your print runs look extremely high to me.  Throughout the 90s, and up until the launch of 3rd Edition, an adventure module for any D&D brand (including Ravenloft, Forgotten Realms, & DragonLance) usually sold less than 20,000 units (some selling as low as 3,000 units).  The original adventures were somewhat higher (since there were fewer available products), but very few of them were above the 100,000 mark, and fewer still above the 200,000 mark.  Anyway, here's what I recall:

1980s: Adventures were selling mostly between 50,000 and 150,000 units.  A few of them (the ones we all know by name) exceeded that.  I think White Plume Mountain was around 175,000.

1990s: Adventures were selling mostly between 7,000 and 15,000 units, though they varied a bit on either side, depending on the brand.  Planescape, DragonLance, and Birthright were on the bottom end of that, Ravenloft in the middle, and Dark Sun and Forgotten Realms were at the top.

Now: Starting with the launch of 3rd Edition, we've cut down the number of adventures from 6-8 per year to 1 per year, so that has cut down on cannibalization of the market.  Thus, sales for a new D&D adventure are now more like 35,000 to 60,000 units.  Keep in mind that these are generally MUCH larger adventures though, with at least 128 pages, rather than the short, 32-page adventures we used to do.

Other manufacturers: Currently, there is a plethora of d20 material on the market, so competition is high.  Thus, most of the other publishers who are doing d20 products are lucky to sell more than a few thousand units.  Even While Wolf and AEG are shipping less than 6,000 of most of their d20 products.  The smaller publishers are barely getting orders for 1,000 or 1,500 per release.  It's a tough market for everyone but D&D.

All of this data applies only to adventures though.  Adventures sell far less than rulebooks do (which is why we stopped doing them.)  Rulebooks are a whole different matter.  In 1989, TSR sold something like 1,000,000 copies of the D&D boxed set in one year.  It was amazing.

Currently, I think they're selling at least 150,000 to 200,000 Players Handbooks per year (probably more with the 3.5 release).

Marketing statistics, found in the 1992 TSR Catalog (thanks to Ralf Toth for this info):

• First-year release sales of the hardcover accessories average 170,000 units (speaking of 2E AD&D hardcovers)
   
• Popular PHBR-series accessory sales average more than 65,000 units
   
• 1st Ed Fiend Folio tome sold 190,000+ copies worldwide
   
• Forgotten Realms Campaign Set sold 175,000+ copies in total
   
• TSR calendars sold more than 75,000 copies annually
   
• Spelljammer Boxed Set (TSR1049) sold 39,000 copies in the first year of release
   
• As of 1992, each issue of Dragon magazine had over 125,000 copies in circulation
   
• Dungeon magazine had a circulation of 15,000 copies

Individual item estimates, organized alphabetically:

10th Anniversary Collector's Set:  1,000

Dragon magazine:

Dungeon magazine (1992):  15,000 copies per issue.  Source: 1992 TSR Catalog

Dungeon Masters Guide:

• First Print:  40,000
• Second Print (includes Alpha & Beta):  40,000.  Source: Story of TSR, Collectable Toys & Values
• Third Print (includes Alpha, Beta, Gamma):  40,000.  Source: Story of TSR, Collectable Toys & Values

Fiend Folio:  190,000+.  Source: 1992 TSR Catalog

Forgotten Realms Campaign Set:  175,000.  Source: 1992 TSR Catalog

Monster Manual (1st print):  50,000.  Source: Gary Gygax

Original D&D Set:

• First Print:  1,000.  Source: various
• Second Print:  1,000 or 2,000.  Source: Dragon #22 (1,000) and various (2,000)
• Third Print:  2,000 or 3,300.  Source: Dragon #22 (2,000) and various (3,300)
• Fourth Print:  25,000.  Source: various

Silver Anniversary Collector's Edition:  5,000 (1,000 of these had lithographs signed by Jeff Easley)

Strategic Review #7:  1,500 (1,200 subscription, 150 store sales, rest were extra).  Source: Tim Kask

Module estimates, organized alphabetically:

B2 Keep on the Borderlands:  1,000,000+.  Source: 1999 Silver Anniversary Retrospective booklet

Ghost Tower of Inverness:  approx 377. Source: various.  Surviving copies have a registry on that page; current tally is 34.

Lost Tamoachan:  approx 377.  Source: various.  Surviving copies have a registry on that page; current tally is 48.

R-series modules:  2,500 of each printed; only 250 to 500 of each sold (the rest were destroyed).  Source: author Frank Mentzer

R-series pre-publication modules:  100 of each, plus a couple (less than 5) unnumbered DM copies of each. Source: author Frank Mentzer.  Surviving copies have a registry on that page; current tally is 6 (R1), 2 (R2), and 4 (R3).

S1 Tomb of Horrors:  250,000+.  Source: Gary Gygax verbal comment

S2 White Plume Mountain:  175,000+.  Source: WotC employee

ST1 Up the Garden Path:  600 or less.  Source: author Graeme Morris.  A lot of controversy on surviving copies, primarily surrounding how many were actually sold vis destroyed.  One of the authors, Graeme Morris, doubts that more than 100-200 were actually sold at the two festivals.  Contributor Ian Wright, who attended the 1986 Games Day convention, bought his copy there for 2.50 pounds, but also remembers a number of copies being distributed to retail outlets in the area (of which he was the proprietor of one).  Most likely the remaining (unsold) copies from the convention were shipped to retailers rather than destroyed.  Probably less than 50 copies survive today.