DIABLO II still sells for around $20 whereas that is also the price for the original DIABLO as well. Because they were great games with tons of replayability value. Not so much with D3.
No matter all the built up anticipation and the hype and the fawning professional reviews, the game (with all its hidden and so hidden shortcomings) managed to disappoint more than half the gamers who bought it.
D3 is overpriced as both the quality of its gameplay and the fact that one pays to buy yet he is only allows to play it on Blizzards' servers - and IF and WHENEVER they feel like it.
The Market will certainly correct this. There is no way D3 will keep the $60 price tag for long. I am predicting $40 by August and $20 the days following Christmas.