There were probably a lot of people still buying it at that price, in sort of a captive market. I'm thinking schools, libraries, et cetera that need to service that population.
Why torture such a noble product as an encyclopedia by putting it in competition with modern internet distribution and price, better that they put it out of it's misery.
What we need are wikipedia ebook devices gets updates via rsync. Something like a Kindle DX with an SD card and wifi.