I think they might be lower than their regular FA versions. The Groudon and Kyogre anyways, because how high the price of a card is depends on two factors.
-Do collectors like it? If they find it as rarer. Money goes up. Like charizard shadowless whatever, Illustrator, to name a few.
-Is it good in the metagame? If so, then also. Money goes up for a limited time, until they're rotated out, then they might stay for expanded, then maybe if anyone goes for unlimited, which isn't even a tournament thing.
Although sometimes the two factors aren't always true, it's mostly like that. Groudon and Kyogre will be higher in the collector department than the competitive one, unless somehow they become competitive. Theta traits probably won't do them any good though. Ray will probably be the most expensive of the three, as he's good in both of those factors. Nonetheless, the RS one will probably see more play, but you never know. Plus-What do I know? I'm probably wrong with all of this. XD