The razors-and-blades playbook
Printer hardware sells at zero-or-negative margin; ink sells at 50%+ margins and costs more per liter than vintage champagne. The economics only work if customers price on the sticker — which is why the sticker is so attractive and the cost-per-page so buried. Every "surprise" ink bill is the business model working as designed.
Why ink costs what it costs
Ink R&D is genuinely expensive (drop formation, nozzle chemistry, paper interaction), volumes are small, and — decisively — the pricing is what the monopoly position supports: locked cartridges, DRM chips, and firmware enforcement. The 50%+ margin is not chemistry; it is market structure.
The tank rebellion
Ink-tank printers moved the ink from cartridges to bottles — $15 bottles printing 6,000 pages at fractions of a cent. The hardware premium repays within a year at household volumes, and the industry's most profitable line (cartridges) evaporates. The revolution is complete enough that the question is no longer "tank or cartridges" but "tank or laser."