That sucks man
You should check out this thread: Chrysler is Paying to Install a New Cam (2006 Owners Should Read This)
My CPS (cam position sensor) started making a ticking sound on my 2003 a week or so ago. I had planned to replace the CPS and the OPDG (oil pump drive gear) assembly. Then I called around pricing it out.
I know for a fact, as per SweetPee's post on Jan 5th in this thread
(4th post, the one with the pictures) that back in January 2010, the CPS was $55 USD, and the OPDG assembly was $51 USD. The gasket was another $2 USD.
I've called around down in Arizona (my cousin's are currently down there), and the CPS is $68, and the OPDG is $272. Huh? Yep....$272.
Bonus: called around here in Canada, the same parts are $95 CAD and $401 CAD respectively, and the dollar is pretty much on par.
Talked to the parts guy up here, apparently Chrysler ran out at some point, as the OPDG part number ends in 'AB'. The old AA part was $95 in Canada. Then apparently they ran out, and Chrysler had to make more, so they contracted them out. The new price is now $401.
This doesn't explain why SweetPee on the Kentucky Krawlers site got the AB part for $61 though
Sorry, this doesn't really help you at all, as the parts are different for the 05-06 models. Is there any chance you could find one at a pick-your-part or other junkers type place? Unfortunately you won't know the condition of the part you find, and it could have the same issues. (you can check the build date code, as per the thread I linked above about the camshaft replacement).
There's a Technical Service Bulletin floating around somewhere that explains exactly which oil pump drive gears had the problem (they weren't hardened properly, so they experienced excessive wear). If you find that you can check the part number / build date for any used part you may find, to see if you'll have the same issue.
Good luck! Sounds like this was a weak point in the engine as it seems to be a possible problem for many of the build years.