If I too could find a $40 505, I would suffer little hesitation to claim it
I do like my 600, but the 505 was ahead of its time in form and functionality. It had all I needed in a quality well-designed straight reader with good battery life. Never used the audio functionality, but I have great memories of having gone through a few hundred books on my 505 before its premature demise...
Thanks for the opportunity to reminisce!