You won't often have spare Soulstones, but this lets you do very funny things like push the Damned into someone, have it swing for 2 damage plus a possible Puncture or Mental Trauma, and then have the 2" push that's part of its attack sequence resolve and deal an additional damage to the enemy due to the Hazarous aura
If you want to trade at TCG mid, you need to determine whether or not youre talking about market price or median price
For instance, a Swords to Plowshares from the original Revised Edition is distinct from a version printed in a recent Commander deck or a Secret Lair drop, even though the cards effect is identical
What's important is that you have a good starting point, and then playing games will inform you if you should bump your numbers around
Each has tradeoffs in convenience, price, and product selection
After that it is the token producers, Basic Conjuration, and the colourless counters buff