Unfortunately, it was out of warranty, so we were forced to buy the replacement unit.
Er... if you still have the old unit then it's worth something. Quite a lot actually. Particularly if you had lifetime service.
Replacing a dead HD in a TiVo is pretty simple -- you just need a new HD, an image, and some technical knowhow (e.g. -- how to follow instructions and connect/disconnect hard drives). If you want details, go check out the Underground on the TiVo forums (http://www.tivocommunity.com
). There are full directions for installing a new drive. The only tricky bit would be getting the image to do the reinstall -- you can find them online though (but not at the site above -- don't even ask there), or if your new TiVo is the same brand/series as the old TiVo then you can get the image from it.
And, if you don't want to deal with any of that, you can sell the dead TiVo on eBay for a tidy sum ($50-100... add ~$300 if it had lifetime subscription).