2010 Sirrus Comp was not full carbon, and did not have 105 stock. I know because I own one: E5 aluminum main frame w/carbon seat stays and fork; Tiagra (triple) components. Mine is heavily modified/upgraded, but pic gives you a good look. So if seller is claiming this (below) is a 2015 Sirrus Elite carbon, nope! That said, if a 2010 Sirrus Comp and in impeccable shape, 600 is pretty high -- even 550 is a generous offer. I might ask 600 for mine, w/full SRAM Apex/aftermarket wheelset/TRP brake upgrade etc.