How much do brine shrimp cost? are they good for fancy guppy fry?

I just hatched out a batch of brine shrimp...a vial of eggs cost me $2.99 and you can hatch them in a bottle...salt cost me $1.99 I have fed them to my fish 3-4 times already and still have thousands of them..lol I am going to try to raise them a little bigger for the fish to ..so I have started feeding them dissolved yeast. They are kinda cool themselves and it is fun watching your fish swim threw a cloud of them and just go crazy snapping them up..not sure how easy it will be to raise them up..but hatching them was very easy then you strain them threw a coffee filter , rinse in fresh water and add to your tank very simple..and it only took 24 hours from start to feeding. Almost forgot to add....I only hatched out less than a 1/4 tsp of eggs..you can hardly see that I took any out of the vial so there are many more hatchings in that vial....you get a lot for your few dollars.