For those most interested in the rare full art promo cards, though, the Eevee Heroes VMAX Special Set is the one
These usually have the same art depictions seen in the full art printings of the cards but instead of having the original colors, everything is dipped in a rainbow foiling
However you do it, these sites provide excellent resources to get started
The Ravnica block, for example, features a city plane inhabited by various guilds
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Darkness Crystal's first ability)
Need more help with Magic the Gathering