Current items that are worth buying to make mass NP now or later on.

Sticky snowball, buy for 25np every 30 minutes, these will jump to 3-6k per in user shops during the CC event.
http://www.neopets.com/faerieland/springs.phtml

Unguberry Elixir
They stock usually 8-12 at a time for around 1400np, selling for 40k-140k all day. Or you can buy low and sell high from user shops.
Edit: these have now dropped down to the 10-15k range, people stopped buying low, selling high.
http://www.neopets.com/objects.phtml?type=shop&obj_type=85

Almost every potion in royal potions, these have spiked to insane prices due to the fearie quest event that's currently going.
http://www.neopets.com/objects.phtml?type=shop&obj_type=83

Retired stamps that will only go up in price, long term investment.
Ring of sloth stamp
Mystery Island Aishas Stamp

If anyone has items they wanna add, keep it going.

This post was edited by Effektivv on Mar 8 2020 10:50am