Instead of trying to give a complete description in my own words, Ill let TCGplayer give you their definition of what this new pricing metric is, then try to elaborate on how it can help you avoid overpaying for something
This is probably why it got a reprint so early into its lifespan
or you can pay 4BR to cast Toil & Trouble as a single spell...If you cast both halves of Toil & Trouble, it's a black and red spell." If it were two separate spells, each paid for separately, then he'd reduce the cost by 2
Reinforce X ( , Discard this card: Put X +1/+1 counters on target creature.) Creature - Hydra Color tag templates(None) Zaxara, the Exemplary Deathtouch : Add two mana of any one color
Munchlax RR69 also has a Rest Attack that can remove 6 damage counters from Munchlax for 2C
That doesn't make them bad or not worth your time, just more difficult to invest in.