Doctor Who Ultimate RPG Collection is pretty much of Cubicle 7's Doctor Who RPGs including the current second edition. The $18 level is first edition books, which have been in previous bundles. The $25 level adds second edition as well as Doctors and Daleks, which is Doctor Who for D&D 5th Edition. $25 level also has the 10th Doctor RPG (1st edition) which was in previous bundles but also has the Limited Edition which is new.

A bit disingenuous in that 45 items includes the 10th Doctor RPG boxed set spit up into 3 books, the 11th Doctor RPG boxed set split up into 2 books (both sets included dice and other accessories omitted from this bundle), and a free adventure.

What's new for me is the 2nd edition RPG books, Doctors and Daleks, and the original RPG Limited Edition Rulebook. I guess good enough to justify $25.

CB7-1304 Doctor Who: The Roleplaying Game Second Edition
CB7-1305 Doctor Who: The Roleplaying Game Second Edition - Starter Set
CB7-1308 DW:RPG 2E Gamemaster's Screen
CB7-1309 A Stitch in Time - 10 episode series (adventures)
CB7-1310 Adventures in Space - creation rules for aliens, starships, space stations, worlds
CB7-1315 The Secrets of Scaravore - 4 adventure campaign
CB7-1334 Sixty Years of Adventure Book One - sourcebook
CB7-1335 Sixty Years of Adventure Book Two

The Einstein Engine - free adventure, 22 pages

CB7-1100a Doctor Who: Adventures in Time and Space - The Player's Guide
CB7-1100b Doctor Who: Adventures in Time and Space - The Gamemaster's Guide
CB7-1122 Doctor Who: Adventures in Time and Space (Limited Edition Rulebook)

CB7-1500 Doctors and Daleks: Player's Guide
CB7-1501 Doctors and Daleks: Keys of Scaravore
CB7-1502 Doctors and Daleks: Alien Archive

Doctor Who Roleplaying Game (12th Doctor)

Time Traveller's Companion
Defending Earth: The UNIT Sourcebook
Gamemaster's Companion
All the Strange, Strange Creatures v1
All of Time and Space v1
Paternoster Investigations
The Black Archive
The Silurian Age
Aliens and Creatures

CB7-1100c Doctor Who: Adventures in Time and Space - Adventure Book
Adventures in Time and Space (Eleventh Doctor Edition)
Adventures in Time and Space - Eleventh Doctor Adventure Book

Ravens of Despair
Medicine Man
Cat's Eye

The First Doctor Sourcebook
The Second Doctor Sourcebook
The Third Doctor Sourvebook
The Fourth Doctor Sourcebook
The Fifth Doctor Sourcebook
The Sixth Doctor Sourcebook
The Seventh Doctor Sourcebook
The Eighth Doctor Sourcebook
The Ninth Doctor Sourcebook
The Tenth Doctor Sourcebook
The Eleventh Doctor Sourcebook
The Twelfth Doctor Sourcebook
The Thirteenth Doctor Sourcebook

Addendum 2024-08-14: Now that I bought it...

- three items are duplicates included in Doctor Who RPG 10th or 11th Doctor boxed sets.
- Doctor Who Starter Set download is a 2-page PDF so that's unfortunate
- GM's screen is correct but it's part of the 2nd edition GM's Guide which is not included

I've bought other bundles with mistakes in them (that are never fixed) so it's not unusual for Humble Bundle.