Brand name computers are not much cheaper in Korea than they are in the US and Canada. 
I can't comment on the UK or SA or NZ but they are a good deal cheaper than in Australia. If you're looking for a REAL deal, inexpensive clones can be picked up quite cheaply in the electronics market near Yongsan in Seoul.
Internet in South Korea
Internet in Korea has one of the highest rates of usage in the world.
Due to strong government support, Korea has one of the highest rates of broadband connectivity, with most households being able to choose ISDN, ADSL, cable, or satellite internet for connectivity. All new apartments in Korea come hardwired with broadband. The average cost of a broadband connection with unlimited bandwidth and incredible up and download speeds (ranging from 10MB-30MB) is $28 USD per month, while an internet connection with unlimited access but slightly slower speeds is only $8 USD per month.
If your apartment doesn’t come with a computer, you will surely have internet access at your school. Outside of school, internet cafés are ubiquitous on the streets of Korea, and time is dirt cheap, most charge as little as a dollar per hour. These places are known as PC Bangs (computer rooms). You will usually see these rooms filled with teens chain smoking and playing on-line games such as Starcraft. A Korean teenager died after spending four days straight in a computer room without food or sleep.
Should I buy a computer in Korea
Getting Connected to the Internet in Korea
Broadband companies offer fast Internet access to homes and businesses through leased lines, cable modems, xDSL, satellite, and others.
Because of competition, prices can change quickly. Companies periodically offer special rates when adding a new service to a neighborhood.
Here are some companies to try:
