Surely you'd never tell the difference between wooden and plastic tyres on a Rover 75? They feel like a sumo suit to drive!
My daily driver is a diesel Mondeo, it sees front tyres off in about 12K as you describe. I have a Sapphire Cosworth with almost 3 times the power which gets driven hard ALL the time, it doesnt wear tyres as heavily , probably because I spend a lot of time keeping it right: all rubber brushes have been replaced with polyeurethane parts, all balljoints are a couple of years old maximum, alignment is set properly once a year etc.
I reckon a lot of wear is caused by sloppy suspension, poor alignment and probably a degree of clumsy driving too.
I'm currently using Conti Sport Contact 2 on the mondeo. I'll gladly take increased grip over shorter life. They're a good tyre IMO. Work the cost difference out in terms of £/week – premium tyres are not much more than their cheaper counterparts and they're your only contact with the road surface. Don't scrimp IMO.
I wouldn't bother with part worns either, got to be a fair bit of stress to the sidewalls unmounting and remounting them.