Pyrowork Wand - Alternative early level wand for players who just NEED to cast fireball.

I'm trying to cook up a homebrew wand for my players who have paid an artificer merchant to make them something similar to a wand of fireballs at a lower price than expected. they're also only level 4, so I only want to give them an item that is still fireball-coded, but not nearly as strong. I do still of course want it to be fun, though.