I've never had a super greasy burger from there. Maybe certain franchises are doing something different than others? It's not the best thing I've ever eaten, but they are better than the Wendys and McD's of the world.
I don't ever buy a shake from there because they are expensive, but when my wife, daughter and I eat at 5 Guys, I don't think I've ever spent more than $25. Little burgers, drinks and then we all split a little fry (which is still plenty). It's maybe $5 more than a similar meal at McD's and way better IMO.