Hoping someone can answer this for us. My wife has an older 13" MBP with the original Leopard 10.5.8 operating system but would like to be able to update it with the new Maverick system. I noticed that Apple is now allowing owners to upgrade to both Lion and Mountain Lion for $20. so that older units can run Maverick. What would be the best way (if at all) for my wife to be able to do this? Would her unit even be up-gradable because of it's age? Because it's still in great condition it seems like it would be worth spending a fair amount of money to bring it up to date. Thanks for any help!