I am very pleasantly surprised with the new set. It has some very playable cards, even in three colors. Jeskai Ascendancy is hot as could be because it is in a seemingly-broken combo in Modern. I have other posts about this card, and also about Villanous Wealth, which I am a huge fan of.
Here is the first batch of fun buys.
I lucked out with Jeskai Ascendancy and got me a play set at $2.70 each before the card spiked. I was able to get all of the other ascendancies for a lot less.
October 13: I speculate that the next set is heavy on artifacts, and others have speculated that Ugin will be a planeswalker in it. Here are "extra turns" buys. These cards are not getting heavy play right now even though they are Mythic Rares. I got both playsets for $5.