This classic se Modern Masters (2013) still has lots of room to grow as Modern and the overall player base grows. I would not be surprised if no further Modern Masters sets were printed, as the next block to see the reprint focus would have been Innistrad, but we're getting "Shadows over Innistrad" instead. Further, Wizards was covering more than 2 years' worth of ground in each Modern Masters release, so eventually they would be caught up anyway. I do believe that Modern Masters was less of a money grab and more of a stop-gap to keep key Modern cards affordable for new adopters of the format. For these reasons, I'm suspecting that we will have to wait longer than 2017 for another reprint-only, premium-price set.
The fact that every card in the set is a reprint means that cards that have recovered from this reprinting will be robust in the fact of future reprintings, especially if included as non-mythics in Modern Masters (some mythics are still susceptible as not much more supply gets injected).
Your best bet, as always, is to invest in singles that are regaining price (and pushing into new price territory) at rates that exceed the set gains.
So, over the next few days, I will be highlighting choice singles from Modern Masters 2013 that are showing strong growth. These are proven all-stars with the shock of first reprint squarely behind them.
First up: Mind Funeral. Modern Masters (2013) was the first and only reprinting.
I think these non-foils will move to $5-$6 by early Spring 2016, and could see $7-$8 apiece by the end of the next year if no reprint comes. These non-foils can be scooped up around $3.00 right now, and some sellers and players may think them to be more like $2.00 each still.
But your better bet is to grab and sit on FOILs. The current ratio of Foil to Non-Foil price is merely ~ 1.1, and even with all of the regrowth of the non-foil price, the FOIL price has not moved a whit. This FOIL version will likely rise to $7-$8 by Spring 2016 (and it will likely spike once supply finals dies to demand). Just look at the "ceiling" effect of the $4.00 price tag - lots of upwards force is being artificially suppressed because of price-snapping and historical reasons).
Note, however, than casual demand usually favors a low FOIL:non-foil ratio, as kitchen table players care less about pimping decks with FOILs. This is because casual players usually play against the same opponents, so the psychological advantage gained by foils exhibits diminishing returns on replay. Consider that Glimpse the Unthinkable (another staple Mill card) has a foil multiplier of merely ~ 1.5, even when considering its lack of reprint and its age.
I would be remiss if I didn't mention that this card is the most potent 3-drop mill card in existence, and that it lends itself to game-winning shenanigans. Mill cards have slow, eternal appeal, and, in my opinion, the deck format is nearing at the tipping point for competitive Modern play. A few more new pieces and Mill may just jump from kitchen tables back to Pro Tours (as it did back in the golden years of Millstone decks). Mind Funeral is typically played as a 4-of, making demand more explosive than for many other cards.
This is a low-risk, medium-term, medium-reward spec.
p.s. stay tuned for more Modern Masters (2013) spec targets to be published over the coming week.