NOOOOOOOOOOOOOOOT to overpriced for the rarity of condition and cleanliness of this vehicle. You really should see it in person to appreciate it and know exactly what it is, before you pass judgement.
Also, it is NOT illegal to own a Skyline (or any other car for that matter) that is not titled and tagged. There are thousands of race, drag, drift, autocross, etc. etc. cars that are not titled nor registered in any form or fashion.
Of course, It is against the law to drive it on the street, just like it is to drive ANY car on the street that is not properly tagged with a license plate. Again, this car can be titled and made "street legal" so you can get a plate for it and drive it all you want. If you don't know how to do that, google it or give me a call, I know people who can get it done for you. There are lots of foreign cars in the US that have been made legal and have legal plates, I'm sure you are aware of that.
FYI...dealers can drive ANY car on the street, without license plates, simply by putting their dealer tag on the back. Their cars are for sale, without ownership paperwork, and therefore not required to be registered and tagged with the DMV.
People should really know ALL the facts and information before blindly posted in a listing that doesn't affect nor concern them.