I started this game when my son told me the name of his clan... Inappropriate for my 10 year old..
I had played a few rounds previously but decided to start a clan for us to play in. I spend a little on both of us... More on me than him.
I buy the least amount of gold to get my free 500. Only when we get the bonus.I usually buy the bonus one too. We are both in champion league now. He is almost 12 now and has lost some interest but we still play daily.
It's worth what I spend for us to have this bond. He is very into games. This is the only game I play.
I have spent somewhere in the neighborhood of 200 on all of us (both my girls played for a bit) I think. I don't find spending necessary but enjoy the game enough throw a little at it every now and then.