Bicycling

The $400 might indicate the wheels and hubs have been upgraded at some time to carbon fiber aero wheels i.e. Zipp. Be sure to inspect the teeth on the rings and cogs for wear and that brakes and shifters all function well. And the most important that the bike be the right size for you.
I learned the hard way that bicycles unless they are some super special collector's dream don't hold their value very well. Looking at the picture of this model at the link it looks like a good tri/TT bike- not a Cervelo P5. That will come when you are sponsored.

https://www.bicyclebluebook.com/searchlistingdetail.aspx?id=20791
Excellent $321 - $330
Very Good $305 - $314
Good $278 - $287
Fair $200 - $206
MSRP New $2,000