The first few learn cards are fairly free, but for Best-of-Three matches, the second set of them starts having real costs
Here are some standout cards which have already been revealed: Special Art Rare (SAR): Bloodmoon Ursaluna ex, Lanas Assistance, Sinistcha ex, Perrin Art Rare (AR): Pinsir, Infernape, Phione, Applin, Cramorant, Perrin, Poltchageist, Heliolisk, Hisuian Growlithe, Torkoal, Probopass Secret Rare (SR): Lanas Assistance Double Rare (RR): Bloodmoon Ursaluna ex, Scream Tail ex, Iron Thorns ex, Magcargo ex Those outside Japan can expect many of the Crimson Haze [SV5a] cards to arrive as part of the Temporal Forces expansion
(10/4/2004) If you pay white mana to activate an ability that can only be activated by spending another color of mana, then any limitations on activating the ability (such as the number of times it can be activated each turn) still apply as if you spent the proper color
It does come at a high cost of 7 mana, though