I would NOT be cool with it because I am OCD.. But that is a killer price so if you are okay with the scratch then rock on...
It's a scratch, I'm sure you'll survive. For the money saved I'd be happy for it to have a dent as well must be hard to enjoy life if a little scratch is the end of the world (just my opinion of course)
If you like the device, put a skin on it with the $$$ you saved. If you have doubts about the device, return it.