Hello, Acreo Aeneas.
I'm in a similar situation --trying to decide where to spend my money. . . and not be sorry because I didn't do enough research. So, I've been doing a lot of research!
For me, the front runner so far is the Onyx Boox, but that's more expensive than your budget allows. I like the looks of the PocketBook 302. . . but it isn't for sale in the USA yet. The PocketBook 301 is nice, but a little over your top figure.
You still might want to check out PocketBooks, though: their model 360 is a 5" screen, very portable, and within your budget. It has plenty of quality features. Check it out on their website, and compare to what you already have in mind:
http://www.pocketbookreader.com/
Here's a video of the device in action. The audio track is in Russian, but you can see the good, clear video.
http://www.youtube.com/watch?v=J4fPM...eature=related
This is in English, but not as well lit:
http://techvideoblog.com/ifa/5-pocke...-e-ink-reader/
Last: a review on this website:
https://www.mobileread.com/forums/showthread.php?t=61908
The drawbacks: no wireless, no audio.
--SilverBear