I'm sorry to say but the Pentium D 8xx line bombed, as did the 9xx for the most part too, except for the fact their a little more efficient and can OC more due to being built on 65nm vs the old 90nm.
Go for a Cedar Mill 3.0ghz, it's the same as a normal Pentium 4 3.0ghz except on a 65nm instead of 90nm, so it's more efficient and can OC a bit more. That and a cheap motherboard with value memory will last you long enough for Intel's new architecture, such as Conroe.