How fortunes are made!

I worked for Hewlett Packard many years ago and was fortunate to be there when the first inkjet printers were invented and remember how expensive they were (around £800 each).

Nowadays you can buy a brand new one which prints, copies and scans for around a tenth of this (£80) but how much do the cartridges cost? These were on offer today at Tesco at £22 each for the double ones and the third one was free but if I had paid for the 3rd one it would have all come to £60!

Who's the clever one!!!