Re: JPeg Detent springs, detent balls?
I would think you could source a couple of springs and ball bearings locally, of course, this would be much easier if you had dimensions. I'm at work at the moment and don't have the bike today, else I'd measure these two parts for you.
Once you have the measurements in hand, perhaps stop in at a local bearing supply, or Tractor Supply/Farm & Fleet to get the bits.
$45 seems really steep considering that you only need the balls and springs (and not the bolts).
I wish I could think of clever things to say in my signature.