Unknown Cervelo Model?

I found this bike on marketplace and have been trying to decide if this work is worth buying?

I poked around the internet a bunch, and can't seem to figure out what model of bike this is. Google photo search seems to think it is a 2008ish P3 Carbon, but I don't think that's right as the seller says the frame is aluminum, and the pics I can find for the P3C are just different enough that I don't think it is

I wondered if maybe it is a P3 SL? I can't find this colorway anywhere online.

Also, would this be worth buying if I'm currently just riding a new Specialized Allez Elite, and am training for an Olympic Triathlon? Or would I be better of sticking off with my Allez? The seller wants $400 for it, and seems willing to come down in price as they know it is an older bike.