Next to the card number are symbols typically, stars, circles, or diamonds that also indicate how common your card is
The only reprint worth over $10 is Door of Destinies, and Id say its safe to assume that original cards may lose a bit of their value with time
Best Ravnica Remastered cards MTG Dark Confidant Cyclonic Rift Chord of Calling Yeva, Natures Herald Teferi, Time Raveler Deathrite Shaman Shock lands Farseek Bruvac the Grandiloquent Divine Visitation There is an excellent selection of cards in this set, albeit with some confusing rarities involved
Getting hold of a Kristoff promo card should be relatively straightforward
Interestingly, at the time of writing, only 54 copies of the Shadowless Charizard exist in a PSA 10, compared to 120 in 1st Edition