karen - i think you should go with your initial instinct - you loved it until your sis made the remark. i'd been lusting for a burberry trench for the last yr and jumped on the chance when i saw they were almost 50% off! to me, the trench is worth it...sure, there are other trenches out there...sure, the average joe wouldn't know it's a burberry trench and it could easily look like a $100 coat to those who don't know. BUT i would say it's worth it for the following reasons:
1. Everytime I wear it/look at it I'll get a little bubble of pleasure/excitement.
2. It's a coat that will (hopefully) last a long time - I'm hoping 10 yrs or so as I plan to wear it on weekends/special occasions/when i feel like it. That way I'll get to use it fairly often but won't wear and tear it so quickly.
3. *I* know it's a Burberry and I couldn't care less if no one else knows.
i bought the ivybridge - i'm done school now and like i was saying, i'm looking for a trench that'll last for another 10 yrs when i'm 34 yrs old with 2 kids running around and likely taking it out on a date night with the hubby.

my only thing would be - make sure the harbourne is the one you really want for the future, and not just the one that's most convenient for grad school. bottom line - my vote is to keep it!
cheapbags - i agree, when i first saw the trench with black/yellow mixed buttons i wasn't a fan...but, it
is the traditional burberry trench button, and i like it now! it sounds like you're not a huge fan of the trench and blatantly regret it. regardless of whether it was on sale or not or that it's the steal of the century because they never go on sale - i think $500 is too much to spend on a coat that "looks decent", you know?

it's sort of like the girls who are absolutely in love with a $1K purse, but buy a $400 purse that they kinda like that's on sale...they'll be happy at first, but their interest in it will fade and they won't really be happy until they get the one they love. if i were in your shoes, i would return it and put that $500 to the coat you really fall in love with...even if it's full price, it'll be much more worth it to purchase that than a coat you are okay with, KWIM?
HTH girls!