This model is perfectly good. However, the laws are still outdated with respect to it. Here are simple proposals:

- hp (or Apple) can sign you up for this, but then they cannot call it "buy" in the shop. Rent an iPhone (Android phone) or install a printer may be what it should be.

- they need to inform you about the price. In EU a shop cannot write prices without VAT. Install for X EUR + Y EUR per month is what should be on the sticker.

- finally, there is the antitrust. If somebody tries to replace Y with ads, this must be legally part of the price. Higher price for consumers is what makes a good reason to split a monopoly.