Biggest way to save when using starsan is to only make u 3L or so for a brew day
It foams so much that the 3L becomes 6L of sudsy foam which is plenty for inside cubes, fermenters etc.
I normally make up 3L, pour 1.5L into each of my cubes, shake shake, pour out the now 6L into a bucket, dump everything in that... and soak my end-of-boil equipment in that.
Also I up-end the cubes into the bucket to sanitzie the tops/threads/lids etc
Similar thing happens on fermentation days... just make up the 3L in the fermenter, shake shake, dump everything, airlocks/taps, etc into that...
I still use iodophor, but only when I'm making up santized water vessels, for instance, when sanitizing a keg I'm going to put water in to make sodawater... or when I don't want foam
at 3L a time, I have 200 doses of starsan