In simple words, the barter menu has been modified so every time you ask a merchant What have you got for sale?, it refreshes the merchant's gold.
To resplenish gold once a merchant doesn't have enough left, simply exit the barter menu and ask again What have you got for sale?
Once you unlock the Master Trader perk, the gold replenished will be multipled by 3.
The delay before the barter menu is also gone, just like Vendor Sale Delay - Gone.
The longer explanation
Merchants keep their barter gold in the same hidden chest they use to keep their inventory, which means it's governed by leveled list laws.
Since the barter gold is technically not on the merchant, you can't pickpocket that gold or temper with it directly, at least not in a live fashion.
To circumvent this problem, this mod adds gold directly on the merchant before the barter menu appears. It's like reverse-pickpocketing, an invisible hand place gold in the merchant's pockets instead.
The final effect is the gold added on the merchant adds up with the barter gold, giving the merchant more gold.
To avoid exploits, the mod removes the gold on the merchant as soon as you quit the barter menu.
Formula
Basis Gold * Gold Multiplier * Master Trader Multiplier + Random Amount
You can change the Gold Multiplier with the console: set TTRGoldMult to X
Details
When deciding how much gold to replenish, the mod find out which type of merchant you're bartering with and select the basis amount accordingly.
Once we have the basis amount, we multiply it by the Gold Multiplier.
If you have the Master Trader perk, the Gold Multiplier is multiplied by 3.
Finally, there's a random amount of gold added. That random amount is between 0 and the basis amount.
Types of merchants
Examples
Arcadia in Whiterun is an Apothecary. According to the table, the basis amount for an Apothecary is 500 gold.
With a 1x Gold Multiplier without Master Trader, the mod will replenish between 500 to 1000 gold.
With a 1x Gold Multiplier and Master Trader, the mod will replenish between 1500 to 2000 gold.
With a 5x Gold Multiplier without Master Trader, the mod will replenish between 2500 to 3000 gold.
With a 5x Gold Multiplier and Master Trader, the mod will replenish between 7500 to 8000 gold.
Unlimited Gold doesn't mean Unlimited Selling Price
To address the gold problem, all the mods I've seen go in the same way: they add a lot of gold to merchants. The unfortunate effect is you can sell 1 item for a disproportionate amount of gold.
My mod address this problem by limiting the total amount of gold available, but replenish the merchant's gold to avoid waiting the usual 2 days or the need to find another merchant.
Investments and leveled gold have no effect on the gold added on the merchant
Including those would unbalance merchants' gold unnecessarily and would require a much more complex solution.
The gold on a merchant will never be greater than 20k
Technically speaking, it's impossible for a vanilla merchant to have 20K on itself. The only way this could ever happen is if a mod introduces a custom merchant with gold on itself. In that case, this mod caps the gold to 20K to avoid the merchant gold bug where the gold get stuck at 30k something and you receive nothing for things you sell.
I chose the 20k value because I didn't want to get in the way of other mods too much. Normally, you'll never get near that amount of gold on a merchant.
You can adjust this limit using the console command set TTRGoldMax to X
A merchant that doesn't use the standard dialogue to barter with you will not benefit from this mod
You could ask the author to add the functionality to his mod or do it yourself. I include the sources for that reason. Normally, it should work out of the box as modders don't tend to stray too far when it comes to this aspect of the game.
Requirements
Latest version of Skyrim Special Edition (should work on normal Skyrim too, but not tested)
Install (auto)
For an automatic install without risk of errors, I suggest you use the NexusModManager
Install (manual)
For a manual install, extract the files from this mod and copy them to the appropriate folders
Compatibility
Pretty much compatible with anything. The only mods that can conflict with this mod are the ones modifying the barter menu structure. Since Skyrim's original launch, only Vendor Sale Delay - Gone did that and I integrated the change into this mod.
Known Issues
Merchants enthralled by Miraak to build pillars in Solstheim will simply not work. The problem isn't easy to fix as they're not considered by the game as NPC, at least not by the console or the Papyrus engine. Since they're not NPCs, I can't resplenish their gold. Fixing this would mean changing a couple things in the Dragonborn's main quest... Let's just say I wouldn't dare try to touch this with a ten foot pole, so I don't plan on fixing this. In any case, you can still find merchants in Solstheim that weren't enthralled and work flawlessly, use those instead.
Do you use scripts?
There seems to be a lot of FUD about scripts so let me explain a couple things. Scripts are part of the game, without them vanilla Skyrim wouldn't work at all. All vendors and trainers are purely scripted. Most of the quests wouldn't work without scripts and there must be countless other scripted things in that game I never thought about.
Scripts aren't inherently bad, inexperienced mod authors are. Because mod authors used badly explained functions in the past, which is the Creation Kit wiki's fault, scripts have been pointed as the cause for all the problems in the world... Like most things in life, clueless people will mess things up, but those that do know how to work with them can do wonders. As a professional programmer myself, I make sure to the best of my knowledge that all my scripts won't cause you any trouble. I also make sure they are upgradable and can be stopped at anytime.
With that said, yes there are scripts in my mod. In fact, the game is made in a way where the barter menu is always called by script so I kinda had no choice. Those scripts cannot mess your game and are extremely fast to execute. I also packaged the sources in case you want to look at them and decide for yourself. Stop worrying your world's gonna implode and enjoy the mod.
Any future plans?
I'll fix problems (if any), offer support and answer questions when needed.