You might notice that the product info pages have undergone a major update and revision. Beyond just adding (finally) the Accessories page, fixing some typos and formatting errors, restoring all the missing cover photos and adding a couple "new" products to the list, I also decided to reflect on this site's focus on the BECMI edition of the game. That's why those box sets now retain their own page, while the rest of the compatible systems (Original D&D, Holmes Basic, Moldvay/Cook B/X, Rules Cyclopedia and the misc. Challenger edition sets) were combined into one page, titled "rule sets and books - other". I'm working on adding the Adventure Modules page and sections for the Mystara (Known World, Red Steel, etc), Thunder Rift and Pelinore Campaign settings, but these are far more involved projects and will take a little while to complete.
I do want to mention that these guides are presented as a reference for people who play the game, not really those who are hardcore collectors. Odds and ends like TSR produced hex paper, dice, graph paper, etc have been skipped. Why? They are extremely hard to find and pricey these days, and to be honest, except from a collector's point of view, they are not necessary to play the game. Plenty of fine vendors produce dice these days, and in this era of Office Depot and Staples superstores, hex and graph paper pads are easy to find and pretty cheap. I focus only on material that actively enhances or facilitates play that cannot be reproduced legally by other publishers today (unless they get a license from WotC, that is).
Sure, some things like character sheets and dungeon geomorph maps can be "cloned", as the OSR community likes to call it. Many great bloggers regularly offer up dungeon geomorph files. In this time of easy printing and downloading at home, geomorphs may finally get the credit they deserve, I certainly feel less guilty chopping up a page I just printed (and still have a pdf or jpg backup copy of) that I do about taking scissors to the copy of Dungeon Geomorphs set 1-3 compilation I paid a hefty sum for on eBay!
For the hardcore collector, I heartily recommend a visit to The Acaeum : Dungeons & Dragons Product Knowledge Database. Their product indices, fully illustrated and footnoted, along with the helpful users on their Q&A forum can help you find just about any answers you need to questions regarding collecting Classic D&D or AD&D 1st edition.
Also, don't forget Drive Thru RPG's D&D Classics web store, the only legally licensed vendor for pdf copies of out of print D&D material on the interent. They're constantly expanding their catalog, so if you want something they haven't added yet, just let them know and be patient!