" Also are any of the lower spec/price models worth a second look ?"
What do you want it for ? if it's just Office work and Internet then the cheapest laptop available is more than capable. If you're buying it for video editing or games, then up the spec to a level that you think good enough and add 10% for the stuff you forgot and that should give you a guideline.
If you're looking at a top spec model because you WANT it then fine, go for it.
Just remember that today's power PC is tomorrows obsolete clunker and keeping up with the Joneses is expensive.