Monolith's Jason Hall updated his .plan pointing to a FAQ of sorts he's added to the official Sanity: Aiken's Artifact web site, which seeks to explain the "talent packs" for the game, some of which will be sold online (while others will be free). Here's an excerpt that deals with the inevitable question if those who buy the "talent packs" have an inherent advantage over other players:

No we are not selling anyone or giving anyone a tactical advantage, because there will always be a FREE talent available to people that is able to COUNTER any bought talent.

You see the trick of mastering Sanity in multiplay is in picking your "play deck" out of all of your available cards right before you go into a multiplayer game. If the server you are logging in to is only allowing 10 talents to be used, you need to pick wisely. It doesn't matter that someone has some bought talents in their full deck...You will always have the counter for it...the REAL question is, ARE THEY USING IT RIGHT NOW IN THE 10 TALENT LIMITED DECK GAME? If so, you better equip yourself with the counter talent! That's ok, you have the COUNTER talent, but the trouble is, there is no way to know if you should use it until AFTER you are in the game playing. So if you picked a bad "play deck" for this round, too bad! If you picked the proper COUNTERS for your opponent’s talents and some good offensive talents to boot, yea!

This is the whole point and strategy of a limited deck game! It is about "play deck" selection, and developing well rounded deck groupings that try to anticipate and cover as many bases as possible based on your play style!