Started playing with a pretty expensive deck (4.5 average) and really like playing the game this way, it's so much more strategic, you've got to know exactly when to fight, when to block and when to just not engage, and you instantly feel when you've fucked something up.
I don't always win but I feel like I have a good shot against anyone who's not just got the perfect counter deck.
My new favourite thing is waiting till a knight gets close to one of my towers then spawning a hog rider and watching the knight chase them all the way back across the map.