Good Idea or Bad Idea

When I first played this game a few months back. I started to have a question. Should I buy or rent my cards? If your reading this you probably had this question also. I watched youtuber after youtuber and all they where saying was rent your cards to the Rank you want to get to. Or buy these cards for your battles. I started to scratch my noggin. How are people telling others to buy or rent certain cards? The game will randomly generate the Mana cap for that battle. Or give a handicap to disable certain abilities. This was really confusing. So I started to think a little out side the box that no one was talking about. How much do I really like this game and how far am I willing to go with SplinterLands? 
So now I am here writing about my journey on this crazy ride. I now have 1 LVL 2 of all the main Summoners. All the cards I went after first was anything that was under a $1. Also lvled those up to LVL 3 or lvl 2 depending on type or rarity. Why you might ask. Its due to the fact. I have a job that I put 50+ hours into a week and a family I try to spend time with. This allows me to be able to play on my mobile device while on the road or at work. Plus if I'm going to be in it for the long run. Wouldn't I want to own the cards myself? I also created a guild for similar people. Its called **Weekend Warriors**. 
I will leave it off with this. Man am I having fun playing this game now. Crazy idea or good idea? you tell me. See you on the battle field or joining Weekend Warriors guild.