Have I apportioned my budget for UK online advertising right?

Should the recent Yahoo changes affect the way I spend my client's money?

[hmpphf]

Hi

I recently agreed this online marketing budget with my client:

Month 1:
Paid for Yahoo, Looksmart UK and Business.com directory listings £425
Google UK, Overture UK, Espotting pay per click schemes £150

Month 2:
Google UK, Overture UK, Espotting pay per click schemes £100
Google US and Overture US pay per click schemes £50

Month 3 and successive months for about a year:
Pay per click schemes £150 a month

I would be interested in your views: now that Yahoo has changed the way it works would I be better spending more money on pay per click schemes and dropping Yahoo?

Have you got any other ways of burning through a client's cash?

It's worth pointing out that all the time I'm working on Google optimisation to maximise free hits.