Here in the UK, the official Amazon cover with light is currently on special offer at £19.99
http://www.amazon.co.uk/Amazon-Kindl.../dp/B003DZ165W
If you ever need to read in dark places the Amazon lighted cover is hard to beat. I was getting through a couple of CR2032 coin cells a week for a clip on light before I got one. Now all I have to do is remember to charge the kindle + the light is much more ergonomic. If you cant find a new one, consider a good condition used one (which is how I got mine).