Weight really depends on cell density. The higher the C rating (cell density) and the storage capacity, the heavier the pack is.
I'd say that it's hard to believe that pack is a true 2800 30c pack at that weight, simply because so many manufacturers make these packs with identical chemistry that it's really not possible for someone to make them lighter. There is usually a variance of 20 grams or so from one manufacturer to another, but 40 grams lighter is stretching it a bit.
For reference a Zippy Flightmax with the same stats weighs 231 grams! So somehow the maker of your battery has found a way to drop the weight by 68 grams without lowering the capacity or max output of the battery and is selling it for $5 less than inferior batteries? Something doesn't add up here.
Here's the same battery
on Ebay that you are showing in your picture. Its net weight is listed as 204 grams, and that's without connectors! It's also priced at $24.35 for the single battery.
Here's the listing for their 3s 2200mah battery on the manufacturer's page. They list the weight without connectors for a 3s 2200mah as 163 grams.
Looks like someone possibly ripped you off.