Candle of curses

[abe ray]

This candle gives the lighter a random curse every 10 minutes for a hour. Not sure what spells or final cost would be though.

 

[ccs]

If it's for NPCs? Then it doesn't matter.
If you're intending for the PCs to make them? Then it costs as much loot/effort as you feel like siphoning out of them.

 

[Eltab]

Bestow Curse with an hour duration and a randomized chart of effects?
Mathematical answer on hold pending 5e coming up with "Make your own magic item" rules.
Looser answer: this item replaces a half-dozen 3rd-level spell scrolls on the loot table.

 

[abe ray]

Bestow Curse with an hour duration and a randomized chart of effects?
Mathematical answer on hold pending 5e coming up with "Make your own magic item" rules.
Looser answer: this item replaces a half-dozen 3rd-level spell scrolls on the loot table.

Don’t forget about the fact that the curses are collumative & a new curse is added every 10 minutes or so.