That is the older PRS-300 5in model from 2009 without Touchscreen or pearl screen. If those matter to you...
Of more impact, it only has 512 MB storage and no wireless or SD so it is very much a PC USB peripheral. It *is* very portable and it bears the Sony logo which seems to matter to some
Here is a good review:
http://www.the-ebook-reader.com/sony-prs-300.html
For a Sony that is fair price for a refurb.
In absolute terms how good a deal it is depends on your willingness to go higher; the newer PRS-350 has been seen at US$109 and the 6in Kobo wireless runs $99.
Or if eink isn't a requirement, the Aluratek Libre with 5in LCD screen and SD expandability has been seen at $49 after a $20 rebate.