OK. Thanks!

My calculation won't be positive...
Due to Veratil's cards list there is 82 different Rare cards.

Considering that one can trade every gotten Rare for other Rare this would give us 82 packs to get all Rares, thus around $220.
To get all in 3 copies: $660.

Obviously, we will be able to trade higher rarities or better rares for worse rares (although if one wants to get all rares, super rares, ultra rares he will not be trading those), or trade bunch of uncommons for a rare and Market will come in handy but that's when the problem will not be solved but will begin
Majority of CCGs have this problem - market in-game values of cards usually lobbied by traders and people excitement.

Anyway, I still think that 1 rare per $3 is not enough for players.

Poxnora (which is really below the suggested level of what CCG should be) offers 28 rares for $45.
TFW offers 28 rares for around $75-80 and this is not good as Poxnora is run by one of the most greedy small companies I have seen so far.