Frugal Fail: Renting your cable modem is harmful to your wallet


Don't rent a cable or DSL modem

Last month, I replaced my cable modem with a new Motorola SURFBoard 6120 (the same one that I would have rented from Comcast).  I did this because I wanted to take advantage of the new speeds offered in my area and my old DOCSIS 2.0 modem could not handle them.  This and a note from my sister-in-law, reminded of how great of a deal it was to own your own modem instead of rent one.

The following table shows how much money I saved by buying my cable modem 6 years ago.  When I first decided to buy my modem, the rental rate was approximately $3 plus tax.  I purchased my modem online, used it for 6 years and then was able to re-sell it on Craig’s List for $25.  Over that time, Comcast raised the rental rates twice.

Cable Modem rental vs. buy

If I use the same projections, and even assume the monthly rate will never rise (unlikely), I can see that I can expect to save even more money over the next 5 to 6 years after upgrading:

Cable Modem rent vs. buy projections


The main reasons Comcast and others say you should rent from them are as follows:

  • If it breaks, we will replace it
  • You are future proofed, as you get free upgrades as the technology improves

Both of these reasons are ridiculous, but let’s address them one by one.

First, “if it breaks, we will replace it”.  This is simply another way of paying overpriced insurance you don’t need.  Cable modems have no moving parts, this means that their failure rate overtime is very low and that most failures are electrical and will happen within the first year.  New modems typically include a 1 to 3 year warranty and as such, paying hundreds of dollars to “insure” your cable modem is simply a huge waste of money.  Regardless, at approximately $7 to $10 a month in rental fees, even if you have to buy a new modem every year, it is still cheaper to buy than rent one from Comcast.

Second, “you are future proofed and get free upgrades”.  Obviously, since you are paying hundreds more for the privilege of “free” upgrades, the upgrades are anything but “free”.  More importantly, it is critical to know that the standards that cable modems follow known as DOCSIS are only updated every 4 to 6 years.  Once new standards are released, it takes cable operators another 1 to 4 years to fully adopt them and phase out the old standard.  This means that if you buy a modern DOCSIS 3.0 cable modem today, you can expect that this standard will be supported for at least another 5 to 10 years.  To add to this, the current DOCSIS 3.0 standard actually supports speeds many times faster than what the average home internet plan offers, this means that it may take even longer for DOCSIS 4.0 to come out and be adapted than previous versions.

If you are concerned that buying and installing your own cable modem will be hard, don’t be.  The steps are very simple:

  • Buy your new cable modem, I recommend going with the Motorola SURFBoard 6120, as it is pretty much the standard by which others are measured.
  • Un-box it, and plugin 3 wires:
    • Power
    • Cable line
    • Ethernet line to your computer or router
  • Call Comcast or your cable company and tell them you have a new cable modem you just bought.  They will ask you for some numbers on the box and then they will configure it remotely.
  • Return your old modem to Comcast or your cable provider and start saving money.

I looked around online and the best price I could find from a non-fly-by-night company, including tax and shipping was, which has it for $88.24 with free shipping and no sales tax in most states.

You can also get it from here ($89.99, no tax + free shiping):

MOTOROLA SB6120 DOCSIS 3.0 SURFboard eXtreme Cable Modem

Or you can buy it from Amazon here:

For another related frugal fail, consider the somewhat dated story of the widow that paid thousands to rent a rotary phone.  However, before you start to laugh, remember if you are currently renting your cable or DSL modem, you are in the same boat.

Buy gold online - quickly, safely and at low prices

3 Responses to “Frugal Fail: Renting your cable modem is harmful to your wallet”

  1. Adam

    Could not agree with this post more.

    Aaron points out buy from,, or your favorite site. Don’t go directly with your cable provider they will again charge you much more for the same product.


  2. Jacob @ My Personal Finance Journey

    I couldn’t agree more! Owning your own modem is the way to go for several reasons! Comcast actually was screwing me over for about a year and charging me modem rent each month for a modem that I actually owned! haha

  3. Amanda L Grossman

    Great analysis! I figured this out a few years ago (though not as detailed as your post:)) when I had Comcast and they were going to charge me $6 per month to rent the equipment. Just makes sense to buy!