I found a used second edition game with the upgrade pack for $20 and that's including shipping. Is it worth getting or should I wait until I have the money to get third edition? I'm really only playing with my Fiancé and her 11 year old nephew. Thanks.
My opinion is both are fine. The 3rd edition has enough improvements to be a better competitive version; but if you just think it is two of you then the fixes in the upgrade pack make a fine version of puzzle strike too.
From the second edition base you can always get the Shadows expansion as a way into the 3rd edition without any duplication of chips.