By default each merchant has between a 15% and 50% chance to have any given item in their vendor list, this mod simply makes those chances 100%.
This mod does not ADD any new items any given vendor wouldn't normally stock, it just makes it so you always get to see their full stock on each reload.
There is a similar mod already on the Nexus All Items with all merchants from start game but that one DOES add new items to merchant stocks; pick your preference All the old mod's functions are now included in the "Cheating Version"


With v1.2 I completely reworked the conditional logic in the original files (whoever originally made that file was a terrible coder)
The gist is that originally that file defined the inventories of the 4 main shops at least 4 times each;
Traveling Merchant lvl 1-7
Traveling Merchant lvl 8-15
Traveling Merchant lvl 16-23
Traveling Merchant lvl 24+
New Serene lvl 1-7
New Serene lvl 8-15
New Serene lvl 16-23
New Serene lvl 24+
Saint Mat lvl 1-7
Saint Mat lvl 8-15
Saint Mat lvl 16-23
Saint Mat lvl 24+
Hikmet lvl 1-7
Hikmet lvl 8-15
Hikmet lvl 16-23
Hikmet lvl 24+

Each one being a completely "new" shop, with its whole inventory defined EVERY time.  I instead made each level transition just add new items to the base shop such that the result is mostly the same outcome, but the files are half the size without ever actually losing anything
(if anything there is a gain of function doing it this way since you'll never lose access to something which was previously on offer)
A lot of work to save 200kb, and not much else, but the original format offended my coder pride :-P