While the keyword costs a creature on your board to be consumed, you benefit from the effect detailed on the Exploit card, as well as letting you play into any sacrifice or graveyard synergies your deck may be built around
The Elemental offers triple the mana production in your lands, mana creatures, and mana rocks which is absurd for the singleton format
Having a well-maintained collection can help you avoid scrambling for cards before a tournament, as well as potentially dodging price spikes
Doing so, however, will involve opening a lot of booster packs (since we doubt you'll get all of the cards you need straight away)
The point here is, Ive basically got the card slot position list worked out, save for Snivy and even then, based on the numbers, I suspect that itll be in the first position in the pack (behind the holo card)