well instant vampire killer just add light for one thing
it nerfs alot of things you'd typically find in dark locations
Authentic sunlight is fantastic for dealing with more than a few undead, and it's great for a lot of Darklands natives.
Well, considering that it takes a 7th level spell to generate a burst of actual sunlight, and only a cantrip to generate ordinate light...
Another to look at it - a permanent ordinary light effect costs 50 gp.
An item that can cast the sunbeam spell once a day is worth 32,760.