Quiet week on the OSR front. On the other hand, we have the 2017 One Page Dungeon Compendium. Personally I am not a big fan of that format. Just because you can make a dungeon on one page doesn't mean you should. Also an old school, if not D&D favorite, Mercenaries, Spies, & Private Eyes which is like a modern Tunnels & Trolls, only good.
OfficialDungeon Builder's Guidebook - Sometime in the mid-90s after eschewing dungeon adventures (particularly in Dungeon magazine), TSR realized "Hey, maybe those dungeon things aren't so bad after all". This is a fairly useful guide. 64 pages, $4.99
Dungeon Master's Design Kit - This is a late 1e era product on how to design adventures, not so much dungeons, $4.99 and 96 pages
Wizard's Spell Compendium Vol 1 - The first of 4 volumes of every D&D and AD&D magic-user (I mean, wizard since it's 2e) spell up to its compilation, which I think was mid 90s. 288 pages, $9.99
MiscCastle Builder - More a guide on how to describe castles to players. PWYW
Monster Wheelies For Labyrinth Lord Vol 2 - More combat charts for 190+ more LL monsters. Because having a separate chart for each monster is so much simply than THACO or Ascending AC and attack bonus. PWYW, but I swear, this makes less sense to me than a single saving throw.
Friday Freebie Ehanced Map 5-5-2017 - Which despite the name, is actually May 12th's map. $1 for enhanced version
Ward's Warrens - A collection of hand drawn cave maps from Shane Ward. Free.