Petrol is cheap ...

... compared to the cost of Printer Ink.....  I have just bought a fresh set of ink cartridges for my Canon printer.  Total volume of ink was 13ml x 8 = 104ml.  Cost of 8 cartridges was £103.98.  That equates to £1,000 per litre. Latest headline average petrol price is around £1.65 - what a bargain....
I have to say that I only use genuine manufacturer ink in my big A3 Canon 9000 printer because I feel the colour match is close on perfect.
I use compatibles in my daily 'workhorse' printer. That works out at £83 per litre.  Petrol is still cheap(er) .....