PC route can be considerably cheaper if you aren't starting from scratch. For example, if you already have a decent PC and an Xbox, you can get a cable card tuner for about $50 per tuner (i.e., $100 for 2 tuners, $150 for 3, $200 for 4, etc.), or less if you buy used. If you have an Xbox, your PC doesn't even need to be connected to your TV at all. My 4 tuner system works great and was fairly cheap since I bought everything used and took advantage of the hardware I already owned. All I really bought was the tuner, a cheap video card, a bigger hard drive and a couple of used Xboxes for $100 each. Now I have a whole home DVR in 6 rooms. All use a normal IR remote so the experience is the same as using a Tivo. My cable card rental is $2/month. I have no DVR or cable box fees whatsoever and get all my subscribed channels (HD and SD). I think Comcast may even give you a credit for not having a box. My remotes were $3 each from ebay, and I programmed them with JP1 software. Since I'm saving at least $40/month in DVR fees, my equipment costs will be paid for in less than a year.
While I would prefer a Tivo-like solution, the initial cost was simply too high for me. An HTPC system does take more effort and skill to set up, but it works very well and saves a lot of energy. My HTPC only draws 2-3 Watts in sleep mode, which it is in most of the time. That's at least another $5/month savings in energy alone over a single DVR.
You may also want to consider switching to satellite, at least in the short term. New customer deals are very good and DVR's fees are generally lower than with cable. Dish is probably the best bang for the buck at $10 for the first DVR and $7 for each additional. DirecTV is substantially more since they charge an additional $10 for HD. They also have the fewest HD channels (not counting sports). These days it pays to switch providers every couple of years.