Caverns of Thracia Humble Bundle from Goodman Games is $18 for the PDFs with the centerpiece being GG's reprint and expansion of Jennell Jaquays' mega-dungeon, a version of which was one of the early D&D third party products.

One thing to note is that there are a loot of duplicates because Goodman Games often releases the same adventure or supplement for both DCC RPG and D&D 5E -- few products are dual-statted. Although to be fair both RPGs have fairly significant stat blocks.

I do own some of this but both Dark Tower and Caverns of Thracia are enough reason to buy for a low price.

DCC RPG Core Rulebook [OWN]
DCC RPG Core Rulebook (Sanjulian Cover) [essential OWN]
DCC RPG Character Folio [OWN]
DCC Reference Booklet [OWN]
DCC Judges Screen - Space Van Art [OWN a version]

Original Adventures Reincarnated #7 Dark Tower (3-volume set, D&D 5E version)
Original Adventures Reincarnated #8 Grimtooth's Old School Traps
Original Adventures Reincarnated #9 The Caverns of Thracia (D&D 5E, deluxe book)
Original Adventures Reincarnated #9.5: Hellpits of Nightfang

DCC Against the Thieves Guild
DCC Dark Tower (3-volume set, DCC version)
DCC RPG: The Caverns of Thracia
DCC RPG: Monsters & Magic of Dark Tower
Fifth Edition Fantasy: Monsters & Magic of Dark Tower
Dark Tower Map: The Lostlands
Dark Tower Map: Redmoon Pass
DCC Hellpits of Nightfang

Monsters & Magic of Thracia

DCC #84 Peril on the Purple Planet (boxed set) [OWN]
DCC #84.1 The Rock Awakens [OWN]
DCC #84.2 Synthetic Swordsmen of the Purple Planet [OWN]
DCC #84.3 Sky Masters of the Purple Planet [OWN]

DCC #97 The Queen of Elfland's Son [OWN]
DCC #98 Imprisoned in the God-Skull [OWN]

DCC #106 By Mitra's Bones, Meet Thy Doom!
DCC #106 Trials of the Trapmaster's Tomb
DCC #107 Forgotten Dangers
DCC #108 The Seventh Thrall of Sezrekan
DCC #109 Beneath the Isle of the Serpents
DCC #110 The Sacrificial Pyre of Thracia
DCC #111 Grave Robbers of Thracia

DCC Annual

Gen Con 2013 Program Book [OWN]
Gen Con 2014 Program Book [OWN]
Gen Con 2015 Program Guide [OWN]
Gen Con 2016 Program Guide
Gen Con 2017 Program Guide
Gen Con 2018 Program Guide

Yearbook #8: The Year That Shall Not Be Named
Yearbook #11
2019 Yearbook: Riders on the Phlogiston [OWN]
2021 Yearbook [OWN]
2022 Yearbook [OWN]

Fifth Edition Fantasy: The Sunken Temple of Set (Free RPG Day 2021)

Fifth Edition Fantasy #25: Seven Days of the Serpent God (Dark Tower)
Fifth Edition Fantasy #26: Against the Thieves Guild
Fifth Edition Fantasy #27: Sacrificial Pyre of Thracia
Fifth Edition Fantasy #28: Beneath the Isle of the Serpents
Fifth Edition Fantasy #29: The Alabaster Tower of Thracia

Dark Tower VTT Pack
DCC Character Class Token Pack (VTT)
DCC 0-Level Funnel Character Token Pack (VTT)