Comparing company pricing can be a little tricky. Each company cells yeast for the same volume of beer at a different pitch rate. So this takes a bit of math to be able to compare everything accurately.
To start, the industry standard is to pitch between 750,000 and 1,000,000 cells per degree Plato per mL of wort for an Ale fermentation. That rate increases to 1,250,000 to 1,500,000 cells per degree Plato per mL of wort for a Lager fermentation. While you can pitch less yeast, it is key to remember that the attenuation, flavor production, and harvest-ability of the yeast will change. For example, decreasing the pitch rate will result in increased ester production, possible lag in the start of fermentation, possible stalling of the fermentation, etc.