jmjasper - Ebay is a choice, but, I really don't do the E-Bay thing anymore / too much hassle and after PayPal etc, (as far as sellers go) they take 11%+).
It's just easier to buy from Amazon, iFixIt, or find a whole-seller for NEW parts.
Now on to answering your question...
In this case, a whole-seller like powerpcmedic.com might have a bad board that they would sell if you call them. They know they won't be able to sell the bad board, and re-working the board would be too expensive. I would suggest that you mention your a student and in kind would post a "thanks" on Facebook and mention their name to other students in your class if they could work a good or "better" discount for you.
On a personal note, it's great to see students like yourself with interest in computers, iPads and electronics in general vs going to medical school expecting to earn high $$$ and ending up in a career that you may hate.
Be sure to visit the forums often, we have a great gang here that are eager to help folks that like to help themselves.