PS Actually, it's worth noting that Aluminium frames are the frames of choice for racers on a budget, pro or amateur. Cheap, stiff, either cheap to replace or robust in a crash, light. The Cannondale CAAD is just one example of an Alu frame (at Evans, a little over your budget) with a strong race pedigree. Of course, if you're doing longer rides, you want your frame to emphasise comfort, but I make the point simply to illustrate that carbon is not the holy grail of bike frames (if you consider cost).
PS Actually, it's worth noting that Aluminium frames are the frames of choice for racers on a budget, pro or amateur. Cheap, stiff, either cheap to replace or robust in a crash, light. The Cannondale CAAD is just one example of an Alu frame (at Evans, a little over your budget) with a strong race pedigree. Of course, if you're doing longer rides, you want your frame to emphasise comfort, but I make the point simply to illustrate that carbon is not the holy grail of bike frames (if you consider cost).