I'm currently racing on a Cinelli Experience; it's stiff & responsive, but not the lightest. Looking at frame options for now. I don't like carbon, so I'm completely discounting it from my selection, so don't bother.
CAAD10 Frame: £800
Kinesis Aithein: £650, but scared of hitting the weight limit as my weight fluctuates from 13 - 13.5 stone
Will consider anything else that's reasonably light & reasonably priced (and made of metal)