OP, I'm new to my current location (Las Vegas) so I've had to figure out the best places to buy chemicals. I went to Home Depot, Walmart, Target, etc pricing everything out and found that, based on freshness of stock (important for bleach/chlorine), my best bet was Target 8.4% bleach at just under $3/gal. The Home Depot 2 1gal KemTek liquid chlorine was from sometime in 2014 so I didn't even bother - not enough turnover in stock. That's something to watch out for with bleach/chlorine but you don't need to worry about that with Muriatic Acid.
A week ago, a local pool store, NPS (has stores in NV and AZ) ran a sale on both liquid chlorine and muriatic acid. The liquid chlorine is 10% and was fresh at ~$5.75/2 gal. The muriatic acid was ~$7.75/2 gal of 29%. Since this was cheaper than Target, I stocked up on both chlorine and muriatic acid.
The above prices are useful for me, but I suspect that prices will be different for you so you'll need to do some casual research.
I don't know how much bleach/chlorine people have on hand, but I'm only trying to keep one month of bleach on hand. I stocked up on muriatic acid though; probably enough to last close to a year. I just need to make sure that there's no leakage.
Read this for manufacture date codes:
http://www.troublefreepool.com/threads/83147-Chlorine-Date-Code-Decoder-Easy-Way-to-Measure-Strength
Basically, if you see '14' or '15' with a 3 digit number, that's likely your manufacture date. I won't buy bleach with a 2014 manufacture date.