A whopping $4/ month for 8 years adds up. $4x8x12=$384...You could have bought almost 10 modems for that price!
When I first got cable from Adelphia, I bought for $10 from Adelphia, a Terayon TJ715 or something like that. It was a horrible modem back in 2003/4 time frame. It would constantly lose synch and thus drop my Internet connection for hours or days at a time even though there was no outage in the area. The techs came out and swapped out 5 of them only to have the same problem. One tech told me they have more problems with those than any other modem they have.
Great...no wonder it was $10.
I originally wanted to rent the modem for $3/ month from Adelphia but with their $10 purchase price, that seemed to be the better deal. At the time, I thought I was only going to be here, my current duty station, for one year, not 4-1/2. I guess it worked out.
I eventually gave up calling them and found a Motorola SurfBoard 5100 for sale at Circuit City. It went for $80 with a $40 rebate. I checked with Adelphia to ensure computability, just need a Docsis 2 compatible modem. After I bought that in Apr 2004, I sold the Terayon for $50 on eBay. The Motorola has been trouble free, knock on wood, for almost 3 years now.
I have a Linksys WRT54g V2.0 that I bought in June or July 2004 and for the most part it's been trouble free. It's currently running HyperWRT + Tofu and it's rock solid. I accidentally screwed up a firmware flash once and I spent about 5 hours figuring out how to reset it and upload another firmware - almost gave up and bought a WRT54GL. What an adventure that was.