I am not sure if I'm amused or insulted by the tone of your reply... I'll go with amused, it's way too late here to get insulted
The 2 BTC was a half joke, of course, as that will probably only just cover the shipping, but still a base line of what you are willing to accept would be good.
As for the USD price, I understand the "I bought it for..." thing, I really do, but that serves very little guidance here. You don't use it, so it's not worth the price you paid when new, it is worth only what you can get for it, assuming it's enough to get you to part with the device. For base I saw http://www.amazon.com/Sony-PRS-505-LC-Digital-Reader/dp/B000WP2RC2
where you get it new for $250 and used starts at $135. Of course these used ones have a bunch of perks attached, like amazon as an escrow, the knowledge that there is some warranty and if you don't get what you ordered you can just take it back for a refund.
Which means that, in all seriousness I can see myself giving something in the order of 5 BTC, maybe a little more if the rate goes any deeper, though I've got a feeling we'll see some mild uptrend now.