I had thought about renting every card myself and last season in the beginning, I did that, until the diminishing returns for renting cards hit and I wanted to play again. I love the gameplay and even if I'm not making as much in playing (Silver III right now without renting cards) as I would in renting out all cards, I stick to it. But I bought a few relatively cheap legendaries, which I rent out the whole season with adjusting prices to maximizie returns. So far, I'm pretty content with the results.

Maxing out common and rare reward cards for silver is my goal as well. But I need some appropriate summoners to do that first.