HP Inkjet cartridges - more expensive than drugs?

I've got a little workhorse of a colour inkjet printer and I need to feed it ink jet cartridges now and then. The beauty of these printers is that they are so cheap to buy that they are almost given away - $99 or less in some cases. But where HP makes its money is in the consumables. While I was changing the cartridge I couldn't remember which was the empty one and which was the new one, so I weighed each on my little postal scale.

The full one weighed 51 grams, while the empty one weighed 43 grams. So for about $50 spent today on the replacement cartridge I got 8 grams of colour ink. So that works out to $6.25 per gram of ink. I would guess that HP buys a 44 gallon barrel of the stuff for not much more than that, so there's a fair bit of profit in the equation.

What do drugs cost? Should I be feeding my printer something else that is expensive and sold in very small quantities? Wouldn't that be a fun sculpture - an inkjet printer modified to be a drug user!

DISCLAIMER: If you take drugs because of what I wrote you are an idiot! And if you modify your printer to take drugs then you are an even bigger idiot - but send photos anyway.

NOTE: HP isn't the only manufacturer guilty of this, but I think at least one other manufacturer has figured-out that people are a little cynical of the prices charged for these consumables so they are now marketing lower cost ink cartridges. Good on ya!