I like the 5 tire rotation so when i looked for my '10 ST, same rim 18" but chrome clad. I didn't have any luck after looking for a month or two, so i went to the dealer, it was only $280.
I picked up My Monty a few months latter and also looked for a rim, 18" Platinum Clad. I too looked ever where. I did find one on fleabay, it was like $350 + shipping or so a while back. I figured the dealer wanted the same price as the chrome one - wrong it was over $700 for essentially the same thing just different cladding. I started talking to the parts guy why the big difference, he just shrugged had no idea, but said he could maybe get an aftermarket through his contacts which is the way i went, came in a little over $360.