Yeah, I too have had no luck finding anything yet. Let's hope somebody wakes up and produces one quick. Amazing hole in the market. Having an app that tells you when apps go on special is something I really miss.
@Skaggz and @Integrals: you have obviously not seen Pandora Box or like iPhone apps (AppMiner & Hottest 100), as you have totally missed the point of tada1096 request. Anyone can search the Android Market. We're after an android app like the a fore mentioned that monitor the market for you, and informs you when the apps go on special or become free. You can set them to watch an apps price. They also post up a daily list of apps that have become free or gone on special.
I'm going to email AppMiner and PandoraBox and see if they're developing anything. They're bound to be surely...