The best way to save $$$ on chemistry is to buy minilab kits. I've been doing it for 30+ years. Unique Photo is one source, and there are many others. Kodak, Champion, Russel and Fuji have been great. I have not had any issues with storage. I'm finally using up the last bit of Kodak Flexicolor and C-41 that was purchased 5 years ago. (got a deal and bought 12, 10 liter kits). I store at room temp, but you can always put the color dev component in the frige. I just opened up some Champion single part RA4 back in Feb. No difference in color compared with unopened bottles. I have all the breakdowns for most kits down to making 250ml for single shots.

The Fuji and some Agfa kits are pellet/powder and I have no experience with them. I only buy liquids.