^lol pretty ghetto down here

you dont need them, aftermarket wheelnuts (tapered) will centre the wheel perfectly when they are tightened
the plastic ones work because they dont actualy take any weight, just centre the wheel

On mine I got vibration/shaking from the front end on the freeway when I forgot to put them on. I thought the tyre shop 'forgot' to balance the wheels; Put on the rings and it was all gone. This was with tapered nuts too.

Tapered nuts will centre the wheel, but if you don't run the rings all the vertical load is being put through the wheel studs. Thats not what they're designed to do, and can break.
A decent grade of plastic should be fine, as they're only in compression, but ally ones aren't very expensive in the scheme of things.

Pfff, i disagree ;p
In saying that i would use the hub rings, myself.

blacky83

Tapered nuts will centre the wheel, but if you don't run the rings all the vertical load is being put through the wheel studs. Thats not what they're designed to do, and can break.
A decent grade of plastic should be fine, as they're only in compression, but ally ones aren't very expensive in the scheme of things.

 
This has always been my understanding of them.
 
Hub-rings have been on my to-do list for some time but it's not particularly important for a car that doesn't move. The scenario in the above picture is what happens when you don't tighten your lug nuts, but I imagine snapped wheel studs would end much the same.

this thread has gotten completely off-topic. ah well, guess ill just try and massage the wheelworx pricing down a bit.

Bringing it back inline. I had a quote done for me by a Tyrepower over in NSW, good store and they always looked after me. They were going to cost the same as you've been quoted.

Got some cheaper poly ones from Tempe tyres. I figure if they do end cracking, I'll just replace them somewhere down the line.

What tyres you getting?