I'm in no way defending HP, and I have no connection to any manufacturer or vendor, but I'd like to relay one story for consideration.
For a large financial services company I was once involved in an experiment in the difference between buying original Lexmark laser toner and a cheaper third party cartridge. We ran two of each across two of the same model of printer until they ran out.
Much to our surprise the original Lexmark printed twice as many pages despite being only 50% more to buy. What was more surprising was that way more paper jams occurred when printing with the third party cartridge than with the Lexmark wasting paper and time. There was also a subjective quality opinion that the original cartridge produced "cleaner, sharper" prints.
So across the 500 printers in the business the Lexmark original was by far the lower TCO despite having a higher unit cost in front of the bean counters.
Clearly it isn't practical for home or small office users to undertake these experiments, but perhaps a trusted publication might? Which? Or El Reg?