I bought mine with Falken452's and yes I paid £500+ for my tyres.
I do not know if anybody has run Avon tyres on the Zed before, but if they are a budget tyre, then caution may be advised.
Like I said before, tyres are the only thing between your car and the road, so you wouldn't want to see the car going off into a ditch for the sake of tyres that cost a little more.
Depends on the perspective one takes, pay less now and possibly pay loads later, or pay more now and hopefully pay nothing extra later...