You can buy ink bottles for the ink-tank printer. You would find that this solution of you buying ink in bulk, and then use it up as you would with any other print job. Your black ink is $35, and your other colors are $25. The ink tank for the black ink is larger, and will consume more ink. This is why the ink bottle for the black ink is larger in volume. This is a much simpler, and environmentally sound solution, and with that said, it makes sense to only offer ink tank printer when that becomes an option.