Yeah, what LOAF said.
According to a 2001 ELSPA market report, a PC game that costs 30 pounds in retail is actually sold for about 16 pounds wholesale. Minus the costs of manufacuring and marketing, you end up with 8.25 pounds gross going to the publisher - in other words, EA probably got just under 30% of the retail price. If WC4 was sold for $40, they would have made about $11 per unit. This means that ultimately, over 1,200,000 copies would have need to be sold. Meanwhile, PC games these days rarely sell over 500,000 copies. I'm not sure if that was the case back in 1996, but I rather doubt that.
Of course, they also had the PSX version to earn money from, but with the PSX, the situation is apparently even worse (at least in 2001), with the publisher getting 5.25 pounds per unit for a game that's sold in retail for 30 pounds - 18%, or $7 for a $40 game.
All in all, if we assume that the situation was similar in 1996, and that WCIV sold 1,000,000 copies on the PC (which seems like a pretty generous estimate), they would have still needed to sell another 430,000 on the PSX just to break even.