You're wasting money if you don't buy your own cable modem

Over the summer, I did something that I'd been meaning to do for years - I bought my own modem.

It was a great move, and if you get your internet through a cable provider, I highly recommend that you buy one. It could save you $120 per year.

That's because like many internet service providers, Time Warner Cable, the company I get my internet access from, charges $8 per month to rent a modem. (Comcast charges $10 per month!) That means that over the course of a few years, I had thrown away hundreds of dollars renting a modem from Time Warner Cable.

I chose the modem - an ARRIS/Motorola Surfboard - by looking at The Wirecutter, a gadget reviews site that I trust. It was about $90 when I bought it, but it's now down to $70 on Amazon. For many people, the modem will pay itself off in just a few months.

But first, I made sure it was compatible with my internet service provider. Here's the list of compatible modems from Comcast, Time Warner Cable, and Cox.

It only took about 30 minutes to connect the modem, and that includes the time I spent on the phone with Time Warner Cable customer service. The company had to change some settings on its end in order for my new modem to work. But most people won't have to do that. It's really easy to set up on your own.

As soon as I returned my old one to Time Warner Cable, the monthly modem charge was removed from my bill. (The modem rental fee increased from $5.99 to $8 right after I bought my own modem.)

My own modem also seems to work better than the one I renter for years, which I'd occasionally have to unplug it and reset. I haven't had to reset my own modem since setting it up.

The modem hasn't paid for itself yet, but at $8 per month, I'll break even in just a few months.