The quotes for the Gold and Plat are same as I got when I called around, about 600 under MSRP, for 2009 xdrive. If you search around here you will see a LOT more of people having gasket related leaks: turbo lines, oil filter housing, oil pans, valve cover, trans sleave, trans pan, diffs...
Not very many Nav or radio related issues. I 'believe' these gaskets above are all covered under Gold and Plat but not the PT. So now if you are at 3500, other 400 over 3 years for the Plat isn't that much more. And will be MUCH easier to sell down the road with BMW warranty. Gold coverage is equal to CPO plus yours with be for 7 years vs 6. Good luck.