I have used dry yeasts almost exclusively (usually Fermentis, but I've tried a few others with good success). I just brewed a Marzen and I thought I'd try White Labs WLP830. I wanted "the best," as it were.
It was not clear to me whether I should use one pouch or two. At $15, I thought I would try one. After two days, there was no activity, so I re-pitched with 34/70 and it's going just fine. So I went back and re-read the instructions. Some people had success with one, while the manufacturer recommends two. It says to use two for "cold fermentation," defined as below 61 degrees, but that makes no dang sense because it pretty much has to be in that range for the yeast to actually work. So why even sell them in one pouch sizes? The thought had crossed my mind that $30 for yeast in a five gallon batch is, to put it mildly, insane.
So am I missing something? Are you supposed to become a yeast farmer and extend the life of that single bag by perpetually using it as a starter? I don't want to babysit yeast and become an expert in fungus husbandry. It seems like there's no way it would be remotely practical to spend $30 for two pouches of yeast for 40 pints max. Almost $.80 in each pint is for yeast alone? Dry yeast is about a third of that cost. Lagers are more expensive, sure, but man, that's insane.