With 87 copies in the Top 64 of the first post-rotation Standard Open, it's no surprise to see the price of Jace, Vryn's Prodigy soaring. Before Theros rotated, you could get really punished for playing a Jace if you ran into a Searing Blood, but with that downside out of the way players are big on little Jace.
The question is, how sustainable is a $65 price tag, and what is the ceiling? Well, that's going to boil down to Pro Tour results. What players do at Opens doesn't often correlate to what breaks out at the Pro Tour, but it's important to note that a lot of actual pros are advocates of the card as well. Gerry Thompson, for example, had four copies in his Top 8 list.
Over the next couple days, we'll see if players liquidate copies and lower the price. It's hard to imagine that anybody had a target price higher than $65 to turn a profit. If this happens we'll see prices dip. If it doesn't happen and/or Jace sees remotely comparable success at the Pro Tour, you might find yourself wishing that you ponied up that $260 to have your set for the next year. It's worth noting that a handful of buylists now exceed Jace's former retail of $40. Whether this number increases or decreases over the week is another great sign of market confidence.