where can I obtain iPhoto 9.6.1 update?

iPhoto is no longer fully supported. You can only update to iPhoto 9.6.1 by reinstalling iPhoto from the App Store. You need to own an AppStore version of iPhoto 9.x.x. to be able to do this. Outside the AppStore the iPhoto 9.6.1 version has never been made available by Apple. If iPhoto does not show in your Purchase History at the AppStore you are out of luck.

See Barney's User Tip: Can't Update iPhoto because it is not available in the App Store

see Can't Update iPhoto because it is not available in the App Store

Basically iPhoto .6.1 is not available for upgrade anymore without a special code from Apple support - if it is not in your App Store purchases list you may be out of luck (it really pays to keep up to date - iPhoto 9.6.1 came out abut two years ago

And Yosemite is well over a year out of date too - the current software is OS X Sierra 10.12 which have many, many new features and bug fixes (still requires iPhoto 9.6.1) and the currnt version of Photo 2.0 is far better than iPhoto (different with a learning curve and different workflows but much better) so if you can upgrade that would be far and above your best use of time and engery

LN

Note: the iPhoto 9.6.1 update shows on my list of available updates from the App Store, but when I click the button, it won't let me actually download and install it since I didn't buy it through the App Store.

It does not matter - updating simply does no longer work for iPhoto, only reinstalling. There will be no fix - it is intentional.

In any event, keeping "up to date" via the app store was not an option since I have the DVD iLife '11 version and thought the direct downloads posted on Apple's website were the latest, which as far as I know only go to 9.4.3.

You could have updated to iPhoto 9.5.1 right after it has been released. When OS X Mavericks came out and the iPhoto updates only available from the App Store, it was possible to convert the DVD iLife '11 licenses to AppStore licenses. If you had upgraded to Mavericks while iPhoto was still supported by Apple, you would now have an iPhoto version associated with your AppleID at the AppStore that can be updated to iPhoto 9.6.1 by reinstalling. This window of opportunity has been closed, when Yosemite replaced Mavericks and Apple stopped the development of iPhoto more than a year ago. Now all you can do is to talk Apple Support into providing a redeem code for you, so you can download iPhoto 9.6.1 from the AppStore. Occasionally Apple Support helped in such cases, if you convince them that you are having very good reasons not to switch to Photos for Mac.

Since I have heard only bad press on the "Photos" App, I guess I am stuck

Photos is just different,and much of the bad press is due to people not seeing how the new features are supposed to be used efficiently. And Photos on Sierra has been vastly improved compared t the first release on Yosemite.

Ok whatever

You are now reaping the "rewards" of being a late adapter

and as to bad press on Photos it is all crazy talk mostly by incompetent people who simply have not learned Photos - it is not the same and needs learning and needs new work flows but any new program does - once you learn it it is far, far better than iPhoto in many ways - since you can not upgrade past Yosemite the version 1.0 you can use is not much if any better than iPhoto - again a "reward" of being a late adaptor

Probably your only option is to beg Apple support for a code to upgrade - they often will provide one and use 9.6.1 which is fine under Yosemite - no print products but otherwise equal to or better than your current version (which does not have print products anymore either)

LN

Thanks for the update. It is good to know that Apple Support is still helping with the iPhoto update in cases like yours.