The prices for PS1 classics on PSN at $6 each (or $10 for the better ones) is far better than the price of an original Xbox game on Xbox Live for 360. Although most of the Xbox games from the 360 online store can be found in brick and morter (traditional) game shops for about $5-10, Microsoft wants to charge 1200 points (about $15) for each download. It should be less considering you are left with nothing tangible, but rather just an electronic copy on your hard drive.
$6-10 for a game you cant find anywhere e;se (exept online, where you are likely to pay a higher price) surely beats $12 for a game that can be found just about everywhere for about half the price.