You can't open Reason files in Reason Essentials. Nor can you get Reason devices other than RE in Reason Essentials.
And I'm not sure how people use Reason live, so I can't really answer that.
My suggestion is to hang out in the KVR market place and keep an eye open (or post a WTB thread...) for somebody selling Reason and Ableton Live.
You can typically find Reason or Essentials for about 50% of retail, or older versions of Reason for around $100 (you'll need at least v4 for Thor...), and Live Lite or Live Intro for less than $50.
Having both would give you the most flexibility, and they work well together via Rewire.
You can also find people selling Reason here in the general forum, but not quite as often.