PSA is a professional grading system that is used to grade how good the condition of the card is. Grade 10 anything typically go for quite a bit ($50+), but they are REALLY hard to get as you basically need to keep the card in a vacuum (not the thing you use to clean up floors, the thing where there's nothing around it including air), according to what I've heard at least.i do have many base set cards, some rare cards too. but what do you mean by PSA 10?