Has anyone replaced their leased cable modem with one they have purchased?

One of my co-workers asked me about this yesterday. She wants to reduce her monthly cable bill as much as possible.

I checked my own Comcast bill and saw that I was paying a $3.00/month modem lease. Not worth it to me, but $36/year is a good dinner to her.

Poking about on-line shows that you can pick up a DOCSIS compatible cable modem for ~$50.00 new. I can probably find one cheaper for her at a surplus place.

The only downside I can see is that the cable company would no longer provide troubleshooting support if there are issues.

Anyone done this? Get any pushback from the cable company?

Thanks!