RPG Maker MV Creating NPC Event with 1 Free Item then store option
Showing how to create an event with RPG Maker MV, for those instances when you want the player to receive a free item, in my case 1 "on the House" potion, then ONE time only. Every other time you speak with the NPC it will open up the shop item.
I hope this helps. I know it took me a bit to figure out, but then again I just startded using this program 3 days ago.