Unfortunately, doing so has two huge problems: First of all, if you are giving someone money and they are giving you an unofficial card of any sort, that is a violation of the very first rule of the Fan Content Policy , which is that things be FREE
Even with that in mind, Codsworth is hardly the most needed reprint for any future Masters set
One is keeping powerful lands in check, from Karakas to Gaea's Cradle
On the other hand, if I wanted to wipe your board with Extinguish All Hope, your Summon: Bahamut laughes in my face
here) but I also need to mention Scryfall.com, which will not only show you the average price of a card, but also direct you to sellers
The most common strategy for fighting discard later in the game is to either play everything all the time, which some decks have the ability to do, or to hold land in your hand to shield you