I want to get a couple of PS2 classics on my PS3 but they require PS+.
If I buy Playstation Plus and buy these "exclusive PS+ only games" after my subscription is over will it let me play the games I bought?
Yes, You will still be able to play games that you have purchased after your PS+ subscription has expired. Even if they are PS+ exclusives.
Only games that you obtain for free from PS+ are no longer playable after your subscription expires.