£3,125

Late last year I needed to buy a new printer.  I have a big A3 Canon for my photography work, but I just needed something cheap and cheerful as a general workhorse. After some research (really confusing) I decided on this little HP printer.  It was the princely sum of £39 - ready to print and with two printer cartridges already installed - and it works a treat. Eventually I ran out of Black Ink - so off I went online to buy a replacement - and that's the little fellow down on the left - at a cost of £12.50.  
On reading my invoice I find that it contains 4 ml of ink.  I couldn't resist :-) - I calculate that HP Black Ink costs £3,125 per litre.
Now,  I've bought some expensive things in my time - but this is somewhere up in the stratosphere.  I don't think I've ever held anything as valuable in the palm of my hand.  
The cost of the actual cartridge must be only pennies.  If you look at my extra it states 'Intended for single use only' and has the 'non-recyclable' logo prominently displayed.
WHAT A B****Y RIP-OFF...