I won't buy it. This developer will drop support of his app as soon as it's not too lucrative. This happened with a desktop version of the Reeder. I had been waiting for the google-reader-api-free version but had to buy Caffeinated app instead.
Mac OSX Reeder is in public beta this fall. He has not dropped support. Like with the iPad version, he was already in the process of rewriting from scratch when Google Reader happened.