if you add an ascending device ($40-$65 for either a kong duck or ropeman) an atc ($15-20) and 2 carabiners (figure $10 a piece) at minimum for what you need, your already running the near same price range for a single device that can do it all, with much less weight. just my train of thought on it.
once you get used to it, i find rappelling with the safeguard just as smooth and easy as using an atc with autoblock
once you get used to it, i find rappelling with the safeguard just as smooth and easy as using an atc with autoblock