How do I get my own copy of iPhoto?
A friend gave me his old copy of iPhoto '11 (9.4.1) years ago when he moved to a newer version of iLife. I installed it and didn't use it for a while, but I've begun to use it quite a bit now, and I like it. I'd like to upgrade to the latest version, but the Mac App Store doesn't want to let me. When I go to iPhoto in the App Store, only the "update" button is available (not the "purchase" button), and of course when I click on it, I get the message that the update is unavailable for my AppleID. Makes sense, since I was not, in fact, the original purchaser of my copy of iPhoto. So, how do I overcome this? I hesitate to uninstall iPhoto '11 because if I'm still unable to get the new version of iPhoto I won't have any copy at all. Can someone verify that uninstalling the old version will, in fact, allow me to purchase the new one? Other suggestions?
If it's relevant: MacBook Pro 13-inch mid 2009 4GB running 10.9.5.
MacBook Pro, OS X Mavericks (10.9.5)