Each one sells for just a few dollars, aside from a select few, and you can often find bundles of the complete set
Izzet Phoenix, for example, needs to have Arclight Phoenix or Thing in the Ice every game, or it will spin its wheels and not go anywhere
If you paid Cleaver Blow's multicleave cost, that spell doesn't have any of the text in the chosen set (or sets, as appropriate) of square brackets while it's on the stack
Even if it's down to two players, you get a 1 discount
This set of 50 blank dry-erase cards is the solution to every "wait, what's that representing again?" moment at the MTG table
In doing this you make your late game much weaker and start to lose to combos through lack of appropriate disruption or to high powered cards in control decks because your deck was full of Force Spikes