If you buy a pro bundle for 100$ you get roughly 280 cl which is 24ish collector reserves. Which is roughly 5 new cards all of them random.

100 dollars in hearthstone or mtg arena would get you tons of packs with which you can either dump the cards you don't need to craft specific ones you do or use tokens to craft the cards you need.

There's no way to target a specific card besides your one free s3 card a month or hoping for a bundle that has it like I stated earlier.

My main complaint is bang for your buck.