How can I reset the inventory of a merchant via console?

Solution 1:

You can do two of the following:

bring up the command console and enter: resetinventory

or

You can perform a wait: I think by T and selecting the time of wait period.

http://www.gamespot.com/the-elder-scrolls-v-skyrim/cheats/

Solution 2:

The command: resetinventory will reset the inventory of a target (select the NPC first) to its default.

If you are just doing this to make the merchant have more money, you should just add more gold into his inventory via: additem f <insert gold amount> after selecting the NPC. After that just sell whatever you want.

In my opinion, 'roundabout' cheating like this is really no different than just giving yourself the gold directly anyway so why bother?