Quote from SmauG »Disclaimer: Following comment is based on what i understand thusfar in regards to the "(For example, 2B and 1BB are different mana costs.)" explanation and understanding of the current modern format
When comparing this card to Tarmogoyf you have to do so in the context of eternal formats and mainly modern midrange, since that's where that card is played most.
The modern format is also one where 4toughness is a very important feature to have on a creature to be considered playable if it doesn't come with protection or some way to gain value from it before it gets removed. Otherwise it has to be cost efficient so that the 1v1 trade into fo a Lightning Bolt, for instance, is worth it.
With the current speed of the format, curve is also of some importance and considering these factors, this guy has to land on curve with at least 4 different mana costing nonland cards in the yard.
To my limited knowledge, only RBx based midrange decks can do that (easilly) using loot/rummage spells. But the decks that run those, don't run Goyf.
I've tried to sequence T1, T2, T3 in existing GBx midrange shells. In those existing decks, my own traverse list could potentially do this, but often this is not the best line of play and heavilly dependent on the opponent's game plan.
* T1: Thoughtseize/Inquisition + Mishra's Bauble
* T2: Traverse + Path
* T3: Demon with 4 counters.
The card definitely has some build around potential but imho this creature will hardly ever be cast on curve as a 4/4 and should be considered a fininsher for the late(r) game. It then can enter as a 4/4 or bigger deathtouch/flying threat, depending on build. Which is very, very good.
I can see myself trying out 1 or 2 of these in my list, but to do so, i want to cut on the top end.
Add faithless looting and surgical extraction and this demon 6/6 on turn 3