I always try Craigslist first. I don't like paying EBay/PayPal/Shipping costs.
The only problem with Craigslist is that people always try to low ball your price and some people really don't understand TiVo. You can spend a lot of time explaining things to them.
S2(03/2006), S3(10/2006) (OTA), TiVo Hd(04/2010), Premiere(05/2012) (OTA), Roamio Basic (11/2013)(Comcast Cable).