The announcement of Eternal Masters sparked a lot of market movement for Reserved List cards. The whole thing is rather stupid, though it would be irresponsible of me to just ignore it. Yawgmoth's Will is a card that has predictably seen a price spike in the wake of the EMA announcement.
A perennial Vintage staple, and a card that is apparently legal in Commander, this was a position that was inevitably going to increase in value given its Reserved List status. This card is definitely a hold, so chiming in now that the price has inflated some isn't great information, and I'm not here to tell you to buy in now that the price is higher. At least, I'm not telling you to buy the Urza's Saga printing...
What I am advocating is picking up the judge promo. With actual demand for this card being relegated to Vintage and Commander, the foil printing makes a lot of sense as an investment option. More importantly, with the non-foil printing seeing movement, it doesn't make much sense that the foil printing hasn't.
$80 is a steep buy-in, and indeed cards of this nature have significantly less liquidity than cheaper positions. That said, the iconic nature of this card and the promise that it will never be reprinted make it a solid place to park some money- just don't make that money your rent money. In particular, if you've been wanting the judge promo for your Commander deck, now is the time to buy. It's definitely not going down.