I brought EQ5 when it was new...and it just didn't click for me. I tried on a few different occasions to read the books and try the practice stuff.
I paid $180 or something outrageous like that only to have it collect dust. I recently sold it to someone on the board...so maybe if there is someone out there that had the same dumb luck as me and just didn't like it, you might be able to get it for $50 or so.
I glad I was able to get a few dollars out of it and pass it on to someone who wanted to use it.