If you can afford it, buy both; at those prices they are a steal. I own a Nokia bought at full price 18 months ago and it was the best device I've ever bought.
I bought 2 more as gifts for relatives and they also like it a lot.
With the Sony at 60$ with the cc, I bought it immediately since at that price you cannot pass it.
For me Nokia is still the main reader for many reasons; the basic one is that I love reading on it, it's a different experience than paper since I use yellow-orange fonts on black background, but nicer for me.