Here's 1 for $99.98. Can I can't believe how cheap DVD writers have become. But the shipping cost might negate the savings unless you are in Vancouver.
http://www.ncix.com/products/index.php?minorcatid=1015
I don't know anything about the Liteon brand. I have the 4X LG 4040 and its awesome. The 8X LG one can be found for about $129 in some places. If its anything like the 4X model, it should be pretty good too.
http://www.a-power.com/parts/roms.htm#dvdrom
http://www.sonexpc.com/?mod=hardware&pid=00000136