Oh, yes, buying your connection equipment is a real money saver for sure, even at $10 a month, $120 a year and in 2 years or so, you are making money on the deal. And, if you move, you take that with you.
Make sure if it is a single unit modem and router in one, that it can handle the speed and perhaps at least a gigabit speed capable even though you are getting 300 speed.