Best budget modem with built in wifi

I'm looking to buy a budget friendly modem with built in wifi. My plan speed is 300 mbps. I need dual band support as I have an old computer that can only connect to 2.4 ghz. I was thinking about getting a refurbished ARRIS Surfboard SBG7400AC2. I don't want to invest $200 when I'm not sure if I'll have Comcast after next year. Does anyone at my plan speed have experience with it? Or any other recommendations? Thanks!