How to determine a faked foundation?

[chameleonmary]

MAC STUDIO FIX FLUID FOUNDATION SPF 15, NC15, BNIB - eBay, Body Lotion, Body Care, Personal Hygiene, Beauty, Health. (end time 22-May-08 15:00:03 AEST)

Hi all! How can I determine if this is a fake foundation? Forgive me if it is bleedingly obvious, I am still a newbie with this!

 

[redambition]

from the picture the bottle looks authentic.

you can compare it to the pic of the bottle on M·A·C Cosmetics (which is what I did). the seller doesn't have a large amount of makeup listed, so it's hard to see if they are selling anything dodgy.

If you are uneasy ask for more photos.