I have 2 Suggestions to add Items at NPC.
1st. As there are Roses and Blowtorch you can maybe add Bubblegum and Pacifier.
2nd. A Money item. As we cant trade more then 20KG, or have in bag more then 200KG. You can Add a item ( f.e. Gold Stick xD ) of wich NPC SELL/BUY PRICE will be 10KG.
So Players can have their Gold as item and trade it. There are items worth more then 20kg. Example 100 or 200kg. And ist not Safe to make a Drop/Pick trade. So Players can trade 10 Gold Stick (100KG ) to eachother and the other can sell that later at NPC when he Needs Gold.
Thank you for your Patience.
Merry Christmas