Update on eBay chain (Ultegra spec) that I got at $17 earlier this week. While it was in transit, I went ahead and got the same HG701 from REI too just to compare the two.
Here are some observations with regards to packaging - slight difference in font type face in some places, font size on the rear of the box and texture of the overall packaging is a little shiny on eBay one v/s matte on the REI one.
Biggest two difference that I can see are 1) inner transparent plastic sheath that wraps the chain. The eBay chain had masterlink and rest of the chain all packed together, while REI one came with a neat little separate pouch for masterlink and another for actual chain.
2) eBay chain can only be had in 116 link length while REI's came with 126 links.
Apart from that, it is VERY hard to distinguish the actual chains from one another - both came with slight lubrication, markings are all correct, even the master links are exactly same not to mention the weights. I honestly don't know what to make of the eBay chain. For reference eBay chain came in at $17 + tax while REI was $40 + tax.