I had a similar use case and recently (Aug) got a used N810 off ebay for ~200 with the 8G microSD card. So far, I love it. I haven't figured it all out yet, but there are tons of apps to try out. Ebay usually lists several with varying options.

You may also look into installing Debian for full Linux support. I'm not sure if this is only for the N810 or N800 for memory usage, but I've seen links to a recipe for doing this.

I'm also looking into contributing, too, to help maintain its life.