Hi @dogs2560 and welcome to our adorable Community 😊 The purchase bundles in the games cost real money. Therefore you need to have money on your account in order to purchase them. I hope this makes it clear. If not, feel free to ask 😉
As @Sukanta_Biswas said, you are not obligated to purchase anything. There are lots of players who don't purchase bundles. It's your own choice.
@mysticalmysty already informed you that we have a contest in the Community. You can join the latest contest on the link below. All you need to do is to tell us which one of the boosters is your favorite and you have a chance to be chosen and earn some gold. Good luck 🤗