Dragons - Prey on the Weak
Dragons can prey on almost anyone and anything, but what should we prey on?
Haste makes waste
As I said yesterday, I suggest to wait and see what happens shortly after release. You can make a list of the cards you already like, but which are still priced to high to be profitable. For every single one you should write down what you expect the card to be worth in a few weeks and at what price you would consider buying it now. Then you just keep an ear to the ground during the small window between release and the first big tournaments with the new cards. After your targets have kept dropping in price below your threshold, you can wait a little more, but you have to make sure to buy in at the first sign of stagnation or upward movement, or when you see the card getting mentioned online by players with a reputation as good deckbuilders.
As I don't want to mess up your plans by prematurely creating additional awareness for the cards with the most potential in the set, which just need to drop first before you want to buy your copies, I will be focussing on the cards that are already cheap right now.
Given that even powerful rare cards can easily end up as 10 cent bulk articles nowadays, you could argue that the cards mentioned below still have a lot of potential to go further down first (or even permanently), but they definitely could see Standard play, so they can have a lot of upside as well. Maybe you want to put those cards on your waiting list, or you want to get some copies now. Either way, these are some of the rare cards that could see Standard play but are on downward trends and already listing below 1€.
More haste, less speed
Surrak, the Hunt Caller is the more expensive of the cards I am looking at today, but also the better one. It has a very reasonable size (being able to trade with the dreaded Siege Rhino) and a powerful ability that should be active extremely often in all green decks. Green Devotion might not want an additional 4-drop, but R/G aggro probably does. Elvish Mystic and just about any non-Caryatid follow-up allow Surrak to come into play and attack on turn3, threatening an absurd beating on turn 4. Being a legendary is not a disadvantage, as he is a must kill for your opponent anyway, so you can just play your second copy after the first one got hit by Hero's Downfall and keep on crushing with haste. Talking of legends: Maybe we can build a deck with multiple legends and Hero's Blade, as just a lonely blade will allow Surrak to come into play and hit for 8, either early in the game or directly after a mass removal. While we are at it, foil Hero's Blade should have potential as an investment related to Tiny Leaders as well. You will be casting your commander multiple times and a lot of other legends in that format anyway.
Depicting in black and white
Radiant Purge is considered too weak for Standard right now, as there are a lot of monocoloured threats in the format and some decks do not even provide a single target for it. Most of the enchantments seeing play also don't get hit by Purge, with Jeskai Ascendancy being the most prominent exception. So why am I even talking about Radiant Purge at all?
Because it could easily become a sideboard card for all decks using white and black, so for all Abzan variants, Mardu, B/W Warriors and Esper control. If the correct conclusion is to run Ultimate Price as your main deck removal, as it destroys Goblin Rabblemaster, Courser of Kruphix, Brimaz, King of Oreskos, Polukranos, World Eater and Stormbreath Dragon, it just makes sense to have the opposite option available for the Abzan aggro match-up or any other decks containing at least some golden creatures as well. Once Theros and M15 rotate out of Standard, we will lose all the incentives for staying devoted to a single colour, and all the aforementioned oppressive monocoloured creatures will leave the format as well, which could result in a much better situation for Radiant Purge in 6 months, potentially resulting in a much higher price.