Can you invest in a shop multiple times to keep increasing the vendor gold?

Can you invest in a shop multiple times to keep increasing the vendor gold?

The speechcraft perk is rather vague about investing multiple times, but I assume it is a 1 time deal for that merchant.

If anyone has tried it, let me know if you can just keep doing it to get more permanent vendor gold.

Solution 1:

You can only upgrade a merchant one time with the Investor perk (Speech 70). However you can get another perk, Master Trader (Speech 100) which gives every trader in the world an additional 1000 gold. [Source: Game and Official Strategy Guide]

Solution 2:

Just one time. I've tested this by myself. Remember not to steal the money after investing. You will lose the investment and also you can't invest again.

I made this mistake, but perhaps Bethesda will fix this so that I could invest again...

Solution 3:

I have invested about 20,000 in the War Maiden shop in Whiterun. I guess it's just a glitch, but I've been able to continue investing.