Yeah, but because they don't tell you (as a separate line item), the cost of renting the cable modem, you're unable to determine whether or not it's a good deal.
I mean, okay, my cable modem is from Time Warner. I honestly couldn't tell you how much the rent on it is, because the internet service is bundled into the rent I pay.
But let's say I did have the bill for that. A mid-range cable modem costs, what, $100? $150? (Newegg lists some going up to $200.) Let's go with $150.
If the bill says my monthly cable modem rental is $5 a month, it would take 30 months before I've saved money by buying my own. If it's $10 a month, it would take 15 months before I've started saving money.
There's other factors, like how often do you need to replace a cable modem because of age or damage, or whatnot. If you're renting the cable modem, the company should replace it if it breaks, right? Maybe there's an extra fee involved in that, maybe there isn't. Maybe it depends on how often you need the cable modem replaced. If it's your modem, and it starts going south on you, you have to pay the replacement cost. So, that has to be taken into consideration.
But if you don't know these things, because the ISP is hiding them from you, you can't make an informed decision.