Note: if you are thinking of buying crates please be aware of the inherent risks involved in supporting any new project. Please also be aware that the developers see this project as a game first and foremost, and not an investment vehicle.
As the game is free-to-play, and you'll receive the entire Base Set cards for free, it is reasonable to ask what reasons are there for buying crates and cards.
In fact, it will be great to see free-to-play users climbing the leaderboards, however, there are advantages to buying cards and crates.
(See this Quick take on cards for a summary of the differences between the free cards and paid cards.)
Cards as collectables
The first important difference is that the free cards are not NFTs (read about NFTs here). The free cards will be permanently attached to your account so you will never be able to use them outside the official Synergy of Serra game, nor will you be able to transfer them out of your account or trade and sell them.
The cards you buy through the crates, the Marketplace or other secondary markets are NFTs and this offers you all the options that NFTs would normally give you such as:
selling and trading them;
having true digital ownership of them; and
displaying and utilizing them outside the official game.
In this way you can confidently build your collection of Synergy of Serra cards in the same way that you would build a collection of physical cards from traditional Collectable Card Games.
Get to know more cards
By buying Transcendent Set crates, and future expansion set crates, you will always have access to those cards to choose them as part of your suitcase, this means you will always be able to actively learn how the cards work in practice.
You will have access to a wider variety of cards and be able to get to know their synergies, strengths, weaknesses and how they can be used against you. This allows you to gain specific knowledge and experience that you can leverage against other players when battling for position in the seasonal ranking ladders.
Although there will be a card explorer, free-to-play users will have to wait for someone else to bring those expansion cards to the table in order to learn how the cards really work in the heat of battle. This means their experience and knowledge of cards will be more fragmented and inconsistent.
Gain XP on your cards
Cards in use will gain experience points. This will happen whether it is you or your opponents who buys them from the River and uses them. Each card has the name of its owner on it so you will know when your card is being used and gaining experience points.
The experience points gained on a card will be used to upgrade that card cosmetically. The XP will not result in gameplay advantages for those who own cards, however, the upgraded cards will be scarcer and should therefore have more value on the secondary market.
Play with your favourite cards
Simply put, by buying the cards you like you'll always be able to put your favourite cards in your Suitcase and you won't be hoping for someone else to bring them to the table.