MDCC, this statement of yours made me think of the following hypothetical situation:
Say I want to start racing, I have an average 80s roadbike and I'm looking to make it faster. What would be the single most cost-effective upgrade that I should make? Lighter wheels? More aerodynamic wheels? STI style integrated brake/shifters?
tyres then wheels a coach when you start getting good
tyres then wheels a coach when you start getting good