Just for fun...

These guys are selling an Asus EeePC battery for $390 before S/H (which 
adds about $10):

http://www.memory4less.com/m4l_itemdetail.asp?rid=fd_10&itemid=1444325172

But you can buy the entire netbook computer with the new battery for less 
than $360 with S/H included.  Maybe they haven't updated that web page for 
a few years!

Mike