I've used refills in the past, and got the following results, print wise, on a printer that cost just over £2. I've managed to clean and reset it once, fully serviced one(Cost £75).
A4
100
2
100
100 N/C Blk 30 Short
150
150
25
10
9 N/C Blk
39
2
100
100
40
40
60
60
5
5
A5
100
100
2
200 N/C Black
200
100
100
A4
2
50
50 N/C Black
Printer set to "Draft", printing in black and white mainly, all full page. All cartridges checked before printing. Now looking at getting a continuous inking system for it rather than using cartridges when the current batch run out.