When you upgrade cash necklaces they never brake! they only decrade if it is 6 or higher, and they have 10% more chance of upgrading
lol
only took me about 150 gems to get ice neclace to lvl 9
lol it took me approx' 750 gems to get my wind neckalce to +9.....lol no cash necklace for me xD.....yet....lol
As for cash necklace tip, despite the fact that a lot of people knew it, I think the tip still cleared up some doubts some people might have had about buying cash necklaces. So thanks for the tip anyways =P.