+1 on dry yeast. I wasted my money on WLP001 for years having never used dry yeast and thinking it was no good. Thank god I found HBT! 2 packs of US-05 instead of a gallon starter for my IIPA = cheap and easy.
I think with yeast washing, you can easily make your liquid yeast last for about 20-25 batches from a single vial or smak-pak with about 5 generations.
Certain yeast like WLP001 that are very neutral maybe not so important, but those such as Wits, Wheats, Kolsch, etc...there is just no way to attain those flavor characteristics without the right yeast, and $7-$8 bucks for 1 vial of White Labs that will last over at least the next 20 batches is a good deal.
Consider buying dry yeast at .99 cents per (my LHBS charges 1.99 for Notty) x 20, that is about the same cost as 3 WL Vials. 3 vials could trickle down to 60 batches!
Although you could wash the dry yeast as well, many don't because it is so inexpensive.
I think the value is in the liquid yeasts, I know it can be argued, but you just can't attain certain flavor profiles with dry.
I don't know if larger breweries, or microbreweries/brewpubs use dry yeasts, but if they don't, I guess there is another point of debate.