Bought a shield (I had 26 gold before speaking with him)
Thinking I had bought it, I went to the inventory to equip it, but it was apparently “stuck” to my mouse, so I’d choose where to place it. Instead of putting it in my inventory/character slot, I mistakenly sold it back to the merchant
I checked the “Buy back” tab on the merchant and saw the shield in there
I clicked to buy the shield back
My money was removed but the shield just disappeared
Update: Went to the zone to the east and the shield was stuck to the mouse (semi-transparently) and I was able to put it in my inventory. Hopefully this helps with tracking down the cause of this problem
Also had the same issue when purchasing a Two-Handed Mace in the starting area with the same steps. I did not seem to have the item at all, however I believe I closed my game before moving areas.