The Sony TR-55 is quite desireable... being it was their first transistor radio... and since they weren't sold in the US back then, it would make them even harder to find today. Of course, this makes them quite expensive if you find one today... IF you find one.
Here's a photo of one... with a little bit of history...
http://www.sony.net/Fun/SH/1-5/h6.html