Hi guys, I've kinda the same problem here, but I've got a 2.66ghz 4gb ram Macbook Pro, with Leopard OS (10.5.8)
My problem is that I live in Argentina, and untill yesterday I didn't feel the need of upgrading my OS (upgrading is waaaay more expensive here, due to Customs policies) , in fact i still don't feel the urge, but as I've purchased the iPhone 5 and it requires iTunes 10.7 (that i've downloaded but can't install).
Therefore I cannot sync my new iPhone with iCloud, iCalendar, Agenda, Find my Iphone nor even any playlists or music.
I actually doubt there are any Snow leopard OS discs left in my country's applestore, and if there were, I'm not willing to pay more than US50 for an old OS, and none told me I was going to need it as I've had no problems with my iPod touch with iOS 6.0.
In fact I might be willing to buy a new Macbook Pro, so I don't find amusing paying a lot for an out of date OS.