For instance, you just hit Level 10. You need 800 NEW XP (either eight wins, sixteen losses, or some combination thereof) to reach Level 11. After which your XP effectively drops to zero and you need an unknown number (probably something like 850 XP) to reach Level 12. Repeat.
Honestly, trying to "level up" (for no real reason other than because they're levels and you're SUPPOSED to earn them - the meager Latinum you gain isn't really relevant) has kept me from buying any cards other than the Elite Sarek on sale yesterday.
If you have a "power deck," people will play you once or twice, realize they can't compete, unfriend you and never look back. You can't get XP that way!