is cosmog a rare pokemon card (PROMO-A #67/92, Promo) If heads {014/028}Cosmog (Miror) | Japanese Pokemon

This doesnt affect the value too much, but the illustrator name (aka artist) for each card is usually visible on both old and new cards

All prices in the list are based on retail prices set by TPC at the Pokemon Center, secondary and tertiary retail spots might have slight price variations, or limited-time offers that differ from the official site

Arcum being Blue also helps

Mana and card draw are the most important resources in Magic, so getting both from one trigger plus whatever rewards you get for sacrificing your creatures is a massive advantage

and Neheb, the Eternal to name just a few

Finally, Sarkhan, Soul Aflame is a valuable card and an interesting commander to build a dragon deck around and get a mana discount while casting them