its like this. the malaysian version is a "localized" version. its meant for sale only in the SEA region, and nowhere else. similar to the thailand USD20 orange box, its not for sale anywhere other than thailand, and won't work anywhere but thailand.

if you buy it on Steam however, in our region since we don't have localized pricing over Steam like how they do in Europe, its considered as buying a US retail license, hence you can use it anywhere in the world, since you're paying US prices. a lot of mumbo jumbo if you ask me, badly executed even though its a good concept that allows people in countries with lower GDP to buy games at lower prices.

and edi, not everyone feels like splurging money on 2 games yo its a matter of preference. I for one, did not even get l4d1 because i didn't feel it was worth the price, and now that l4d2 is coming out, i'll likely only be getting it on 2 conditions:
1. 50% off weekend
2. no l4d3 next year (this of course is also dependent on how they merge the games together). heard some news that they're planning something to enable the l4d1 and l4d2 communities to stay together, if it entails completely scrapping the l4d1 engine and installing the l4d2 engine over it while allowing us to play the old campaigns, then huzzah, i'll be on the bandwagon with y'all soon.