I have a 52cm Specialized Allez E5 frameset that I've been keeping as a backup. It's new/never built/uncut steerer. "Black Widow" colorway (anno black frameset, matte black Specialized decals, red accent decals):
https://www.specialized.com/...e5osbbframeset/37726 Includes fork from the Tarmac, 27.2 aluminum seatpost and clamp, headset bearings/top cap/steerer plug, BB30 bearings and clips, and press-in BB adapters for use with Shimano cranks. Internal rear brake routing.
I'm currently racing a twin to this one. My previous bike was a Cannondale CAAD10, and the Allez stack/reach/other measurements are within millimeters of the CAAD10 (geometry chart shown further down on the page linked to above).
I'm looking to get $650 for it plus shipping, which I know is slightly over your budget. That said, let me know if you're interested or if you'd like pictures.
--Gene