Take a look at the reviews of this radio on eHam.net. It is a pretty complicated radio and depending on what you are looking to listen to, it may not be the right radio. It does not do trunked or digital. As for the $500.00- it looks like that is a good price- again if this is what you are looking for.
You may want to post this question in the SWL section.
Sounds extremely hokey to me short of actually picking it up in person. They are over $2000.00 new. I'd say it's out of the norm for someone to get such a Christmas gift. Then, considering that it's way too complicated for the recipient makes it even more unlikely. I have a hard time thinking that someone would drop that kind of $$ for a Xmas gift for someone that was not a very experienced monitoring enthusiast.
If it is a real deal, and you can see it in person and confirm it's working, grab it QUICK. Even if you don't use it you can make a pretty decent profit on it considering its condition. I own one and it's the best receiver I have ever had.