Looking for Arctic wheel cap centers

[perussell]

Hi, does anyone know of a source for Mazda wheel centre caps (other than mx5parts.co.uk and the dealerships). I have an Arctic with the 20 spoke alloys which have just been refurbed. Unfortunately this has highlighted just how shabby the centre caps are but I have now learned that the centre caps on this wheel style ar 50mm in diameter and not 56mm which seems to be the standard for most other MX5 models.
The standard caps retail at around £6 to 8 each whilst the Arctic caps, which are nothing more than a silver centre with a chrome effect Mazda symbol are a minimum of £20 EACH.
I am reluctant to pay this kind of money for something as small and simple as a wheel cap though it is increasingly looking like I might have to.