If you are just settling for gold 3 with this much level, then you are missing on your adventure. Also the rental price is not the same when you start a season and move forward. If you are playing and defeats a low level player while fighting, it doesn't give you happiness but if you defeat a high level player with low level, then definitely you will find happiness. Also low levels won't cost you much for renting. I play with level 3 cards and still reaches gold 1 , although my playing style is different, I play daily and daily quests are my income , not the actual Dec.