I am suggesting that a simultaneous lowering of price and availability in another large marketplace might offset the price reduction and even net him more revenue.
If i read what he was trying to say, I think he was more suggesting to lower the price to $1.99 in both market places. Even though lowering the price on Amazon netted less profits, even though more copies were sold, though not enough to offset the price reduction. By adding the additional, possibly larger market place, this price reduction could net more sales and be maybe more overall revenue.
You don't have to know how the computer works, just how to work the computer.