I recently noticed this after selling something I hadn't intended to and reloading from when I entered the store. Unless you exit the game completely and start again, the most recent amount of gold held by the merchant is REMEMBERED when you reload. So if you sold everything you could, bringing his gold to zero and then reloaded you would still have your stuff and he would now have no gold and couldn't afford to buy anything.

It also seems to work in reverse, and this is the exploit part: you BUY everything cou can afford, increasing his gold. When you reload he can now afford to buy more of your stuff than before. I assume you could stack this, buying and reloading several times. Specifically this is noticeable in Whiterun inside the alchemy, general goods and War Maidens stores

Can someone check this on other-than-PC systems? It may even happen with outdoors merchants, but only if you reloaded from the time you entered the city.

Any ideas on WHY this happens?

Yeah, it's a glitch with how the game keeps track of its state across reloads.

You can also save -> kill the merchant -> reload to reroll their inventory if you're trying to buy something specific.

the game does a horrible job of memory managment and stores useless crap in memory buffers even across saves. That coupled with how it never cleans up items/ashpiles/nirnroots will eventually lead to major issues down the line.

its a bug..and an exploit but not really anything gamebreaking or anything you should feel bad about abusing. If anything, merchants should carry more gold based on either your level, or your speechcraft, or both.

On XBox 360, and I tried with Tonilia, the thieve's guild fence. I had done all the upgrading the guild quests, so she has 4000 gold every two days. I saved, bought all her enchanted weapons, expensive potions and such, then checked her gold. It was over 11,000, but when I reloaded oddly enough, she had 2199 gold. Did it twice with the same result. It could have something to do with her being a fence, the amount going over 10,000 or her being a unique merchant in that her "normal" reserve is upgradable in four stages by quests. But at least in her case, it actually made it worse to give her more gold. Upon exit to dashboard and restarting Skyrim to load the save, she had the predictable 4000.

I knew I saw some that I had previously picked.

it's not the picking, it's their glow, unpicked glows never refresh like ash piles and if you leave the same nirnroot unpicked and revisit it several times the glow will become super bright

I always wondered why the glow wasn't on the nirnroot itself, but on its place and therefore continued to shine after being picked.

That explains the second sun I noticed the other day! It did seem ridiculously bright, but I didn't know why.