I don't think they'll make Rubies and Sapphires more likely to drop. Some 1.5k armor in Cantha still require ludicrous amounts of Monstrous Fangs/Claws that are totally random. Vabbian armor seems to be an expensive "1.5k" armor that will require you to buy lots of Rubies/Sapphires.
FYI: You can trade Trade Contracts for Diamonds, Rubies, and Sapphires. So they will be worth a lot less when the quests finally activate for them. (boo I wanna sell 30k diamonds )
i would hold off buying rubies and sapphires at the moment snce you can apparently trade them and they are bound to drop with an increased rate if they are used in low cost armour