Even the small Jobo 1510 tanks state 140 ml for roll processing. With the 3x1l kit this would mean I have 7 test runs before I have to get new chemistry ....
The 3x1l kit, at least the one I know of, is for 1+1 dilution, so you don't have 7 test runs, but you have 14 test runs (or 7 test runs and 7 prints). Of course, using less chemistry in a smaller drum (with smaller sheets) will save you even more, but... this is already a 100% difference.
-- A sinister little midget with a bucket and a mop / Where the blood goes down the drain --