http://www.adobe.com/products/catalog.html
https://creative.adobe.com/plans
In the US, Adobe single-app pricing is $20/month and full-suite pricing is $50/month so if you are eventually going to use more than just two apps, it’s more cost effective to buy the entire suite subscription. Do you not also need Premier Pro? Also if you need Photoshop, as you say, there is a PS+Lightroom plan for only $10/month.
So PS+LR for $10/month + AE for $20/month is $30/month unless you need another app, eventually, then you still might as well go with the entire suite.