It's only fitting that Vampires should be competitive in an eternal format.
Vampires just got their Commander in Drana, Liberator of Malakir from the new Battle for Zendikar set, and she signals a slew of new tech for the tribe. Preorder prices show that this is the breakout mythic of the set. I think it will look a lot like Brimaz, King of Oreskos while in Standard. However, due to the age and depth of the Vampire rosters, Commander demand for this Drana will be enormous as compared to silly ol Brimaz. Also, and I only noticed this recently, she is an ALLY, too!
FOILS are still only around $30 each. As a short-term hold this could make you some big money fast, if you're comfortable with 40% profit margins as your likely maximum (I think they'll peak around $50 or so, and only for a month or two while in Standard). 3 years down the line, FOILS will return to that high-water mark due to Eternal (especially Commander) demand. My plan is to wait until this new Drana leaves Standard in 18 months, then get a couple foils for eventual Commander demand at that time, for more like $20 each. It's a black card with a lot of white in it, great for FOIL.
Perhaps more interesting than jumping on the Drana bandwagon is considering her effect on Vampires builds in general. My favorite vampire for a tribal vampire deck is Vampire Nocturnus. He was a solid $15-20 for a few years, back in his day. He found his bottom about two years ago, after M13 left standard, and he's started a slow swing upwards on eternal demand. Look at the jittering circled in red in the prices below (green in low, blue is median, yellow is foil median): this signals shifting allocation of cards. People are buying these. I would not go deep on these guys right at this moment, but I would watch them like a hawk and get ready to pull the trigger.
He was poised for a year of percolation and slow growth... that is, until Drana, Liberator of Malakir. With only two non-promotional printings (M10 and M13, both at mythic), I think the obvious new demand will outpace supply even moreso than is currently happening. When reprinted into M13, he gained back most of his value, just because he was still so strong in Standard. This protects him from value loss due to a reprint back into Standard.
A reprint of Nocturnus in a Commander deck would destroy the value of non-foil Vampire Nocturnus from M10 or M13, especially since this is the market segment from which much of the new demand for Nocturnus will arise with the new Drana. Unlike Felidar Sovereign, which was just reprinted in BFZ as a rare, demoted from a Zendikar mythic and saw it's price drop from $12 to like $1, is hardly stackable and is a very specific role-player that is only valuable in a constructed deck in an eternal format, Vampire Nocturnus is an easy build in any format, extremely potent, and stackable.
If reprinted as a mythic, a think Vampire Nocturnus would re-renter standard as a $12-$15 card (especially if it's in the next set or block, to pair with Drana and her kin). If it's reprinted into Standard as a rare, I think it would maintain a $5 price-tag due to its overwhelming usefulness in Standard.
FOILS are a steal right now, at well under $10 apiece. If no reprint into Standard occurs, you can expect a FOIL Nocturnus to fetch $20 or so within a couple years.
Grab a fistfuls of FOILS for a low-risk, long-range hold. And in the meantime, Drana may well continue to shine backwards into Commander and Modern and make this guy a shorter term payoff than that.