I agree, bread yeast is $12/2 lb (almost a kilo, here - https://www.amazon.com/Red-Star-Active-Yeast-Pound/dp/B005KR0MZG ), I would think the process is similar for bread and beer yeast. Maybe they make it from malt as opposed to regular wheat which makes it more expensive.
If I were you, I'd get myself a big bag of active dry yeast (I get mine off of amazon: https://www.amazon.com/Red-Star-Active-Yeast-Pound/dp/B005KR0MZG/ref=zg_bs_6492285011_3?_encoding=UTF8&psc=1&refRID=6RGTDZ4VKM9HTWYD12V2) and make your own dough at home, unless time management is difficult. I use Gordon Ramsay's recipe (https://youtu.be/vcfNpDtVqOw, and there are print versions available online), which only takes flour, yeast, bit of sugar and salt and olive oil. It makes two very large crusts for me (though I like it thin). So I usually make one pizza, then keep the dough for a couple more days and make another that week (or some calzones or something). Not too difficult at all, and pretty tasty. I used to get premade dough and mixes, and found this to be a better end product for only a bit more effort/time.
Either Costco or Smart and Final carry big bags of Red Star yeast. I think last time I bought it was only $4-$5, but the Amazon price seems much higher
https://www.amazon.com/Red-Star-Active-Yeast-Pound/dp/B005KR0MZG
Are you using a scale for your measurements?
I use Roberta's recipe for my dough, and it turns out great when I weigh the ingredients on a scale, but when visiting family I use measuring cups, and I end up having to add a LOT of flour to get the right consistency.
I use active dry yeast. I bought this 2-pound bag on Amazon almost a decade ago and it has lasted in my freezer, believe it or not.
http://www.amazon.com/Red-Star-Active-Yeast-Pound/dp/B005KR0MZG
You can buy this at costco, I just did a couple weeks ago. Works well, although I'm not baking croissants :S