Emeria saw a reprint in Commander 2014. She has offically bottomed and rebounded, with a vengeance. The original printing is shown in the first graph below, and the reprint hammer came down hard in November 2014. You can see the price fall breaks pretty cleanly into three stages (the third is a short flat plateau). This card was on it's way to $6.00. This was Zendikar. This has not been around for 12 years or something, it's relatively recent yet saw casual demand take it over $4.00. This will be $4.00 again by next Spring (unless they reprint it again soon, which seems quite unlikely to me). Original foils didn't move at ALL with the reprint, and are sure to double up sometime within the next year or two (though they show no movement right now). Right now, I'd try to pick up cheap copies left over from the 2014 Commander glut or deflated Zendikar non-foils. Anything under $2.00 is a good deal, and getting better daily.
More generally, check Commander 2014 for reprints that have bottomed out. There are a few. Buying reprints of proven cards, at the right time after their reprint, can be low risk investment strategy. See Life from the Loam.
And this second graph shows the Commander version. Couldn't be clearer. Lots and lots of room to grow.