I would be VERY careful in this situation. I bought my last computer, a black macbook off of ebay. I saved ~$300 off the retail price (like $100 off the edu price); however, I was VERY close to losing my parents $1400.
A guy was selling discounted iMacs, Macbooks, and other Apple hardware on eBay. He had good feedback, and his feedback reviews were FROM apple purchases, so I figured it was legit. I pulled the trigger and ordered my laptop. After a couple weeks, I stopped hearing from the guy. I didn't get any shipping updates, any emails, anything. I searched for his account and found a thread on macrumors. Here's a link to the last page, it kind of summarizes things:
https://forums.macrumors.com/threads/419818/
Basically, he shipped a bunch of orders to the first group of customers, then when word got around and he got a TON of orders, he just took the money and ran. I got REALLY lucky and got my macbook, but a lot of people didn't.
Looking at your link, it doesn't seem like a particularly great deal; however, I would be very wary considering his feedback.