I messages him asking if the box is included.

So I bid on e amp and won it at $350. When he shipped it he said that he shipped it with a brown box. I messages him saying that I wish he had asked first if he was going to change it because the only reason I spent so much on the amp was because it included its original box. I got no response.
Once the arrived I checked it. First off, it was in a brown PG box. The box was sealed with duct tape. I gently shook the box to see how tightly it was packed. I heard the amp flopping around in he box. With 1 pull all of the tape came off. When I opened the box it was packed with a couple of cut sheets of bubble wrap. Luckily the amp did not appear damaged.
The plexi was in great shape and the paint had the noted scrapes that were mentioned in the auction. He dc offset was off on one channel but the amp works.
I messages him about the box. After several messages back and forth I was given the option to return the amp for a refund or pay $30 for the original box.

I then offered him $20 to send me the box, but I asked that he ship it inside another box to protect it. He responded saying that I a welcome to return the amp for a refund.
I am waiting to hear if he will pay for the return shipping. If not then I will keep it but give bad feedback on eBay.
Cliffs notes: amp came in good shape, but it was poorly packed and did not include the original box, which was originally promised.