Buy them an Ooma instead. VOIP phone, you pay for the initial box (around $60 on sale lately) and then all you ever pay again are the fees/taxes for phone service which in my city is about $3 per month.
Unless Time Warner tries to give them the run-around that it's actually cheaper to bundle a phone in too, rather than having just internet + TV.
Oh, the only additional expense with Ooma is if you want to keep your same phone number, they do charge like $30-$40 to transfer your current number over. So you could be looking at a roughly ~$100 up-front expense with Ooma for the box + number transfer, but if it even saves them $10 a month you're still coming out ahead in a year or so