As far as I can tell, youve got six months/two seasons when it starts declining, and thats when I advocate you sell everything youre not using for Standard
Chien-Pao EX, Alternative Art, is currently selling for around 50 (or $60-$65)
If youve gathered all the required cards but havent received the reward, try clearing the cache from the in-game menu
When it enters, you can discard a card to tutor up any creature from your library, which makes it great to dig out combo pieces or silver bullets on demand
Hyper rares are the newest known gold Pokemon cards so far, so if you ever encountered one that is not the said rarity, try to double check and see the source of that card, as well as the set it came from
Path of Ancestry ($2) I like Red XIII being on the cliff here, but I also love a special version of a card in 130,000 decks on EDHREC getting a special version so cheap