I use these labels from Meritline. About $20 per 100 plus shipping. They're not as good a bargain as you might be looking for, but they're about half the regular price of the Neato glossy labels.
I once got a good deal on Neato glossy labels, but not as good at the one you got. They were on clearance at Wal-Mart about a year ago for something like $5 for 50 (or about 1/4 their regualr price). I grabbed up all they had.
Maybe someone else will come up with something cheaper. The Meritline labels are very good and reasonably priced in my opinion. Good luck.