Imagine $5 start, buy buy Doctor, trash 2 cards. Draw remaining 3 in deck, you have 6 cards not in hand and draw 2 of them, getting Doctor, name Copper, trash 3 of them. At that point, you have 1 card in draw deck, Doctor and 4 in hand. Say you buy a Silver, that a 7 card hand at the end of turn 2. Pretty dang strong for fast trashing if you manage a $5 start.