The fall in market value is a dramatic reversal from 2006, when total sales value measured by GfK increased 11 percent to top US$7 billion for the first time.
For example, bargain-hunting Chinese buyers chopped more than US$150 off the average price they paid for PCs between 2006 and the end of 2007.
The number of computers sold increased dramatically because of a continuing rise in the popularity of notebook PCs in the region, while the number of desktop PCs sold increased at a more sedate eight per cent.
Total sales value for both desktops and notebooks fell by approximately the same rate.
"The rapid notebook expansion in most Asian countries due to the eroding price points continues to drive volumes," said Gerard Tan of GfK Asia.
Malaysia saw the strongest growth in the region as consumers switched to branded desktop PCs. PC sales volumes rose 68 per cent, and sales value was up 72 per cent.
GfK's survey was based on retail sales data from 11 of the largest markets in the region, including China, India, Australia, Korea, Taiwan, Indonesia and Thailand, but not including Japan.