Should I buy this bag? Help me decide!

$385 for a $1400 bag seems like a good deal to me. I would not be concerned about the pen marks on the bottom of the bag. The one on the front would concern me some. I would check on the return policy and if it was returnable, take it home and see if I could get the mark off. If not, then I would return it.
 
Personally, I wouldn't buy a new bag that has pen marks even if it was inexpensive. If I am buying new I want it to look new, otherwise why not buy a used bag for cheap?
 
If the marks are small, but visible when using it, see if they will give you an additional % off of the price. If they aren't visible when in use, I personally wouldn't worry about it too much and consider it a great deal for $385.
On another note: the bag is beautiful, no doubt, but my sister has the small version and complains all the time about the buckle clip. I guess it is not that easy to manuever quickly or for everyday use. She leaves her's un-done all the time and it drives me crazy when I see that, becuase the flap kindof "hangs" open. I always have to clip it closed for her!
You may want to test it out before you purchase it, and see if you think the clip will bother you.
Good luck!