I was noticing that it costs about 6 dollars for a vial of yeast, and about 3.50 at my local brew store for enough DME to make a proper starter to double the cell count in a vial. So, it's either 9.50 for a vial of yeast and a starter, or 12 for two vials. Is there any advantage of making a starter over just pitching two vials?
You already said it's not a money thing, it's just a convenience thing... but I think you math is off. I can get a pound of DME for 3.50 - and with that I can make a little more thant 4 liters of starter (I use 100g/liter). For most 1.050 beers, I only use 2 liters - which Jamil says is enough to double your cell count. I pay almost $7 for a vile - so it's $8.75 vs. $14 for me - enough to buy at least 2 more oz. of hops... I don't mind the extra time - as others have mentioned it "commits" me to brewing two days later.