That's the right stuff. That's also the crappiest looking live LFS I've ever seen. But hey, it's just $5.
Granted it's dormant, but even dormant moss should look better than that. In fact, it looks like the seller chopped off the living few inches and is selling the dead, or almost dead, undergrowth. I don't see one single growth point in that picture. It would be great for potting media, but if you want to grow it as a top dressing you can do so much better than that.
Lay it on appropriate media, like LFS or peat, and keep it watered. Put it in full sun after acclimation. Enjoys frequent overhead watering.
The Sphagnum I send out is by the gallon, very green and fluffy, and not elongated like that. Only once have I sent out dormant sphagnum that was not attractive, but I gave the person who asked for it fair warning that it looked like crap since it was winter, and he was happy anyway. I'm not saying I can provide you with any at this time; I'm saying that I would not buy the Sphagnum in that link when you could do SO much better. Last year I sold a gallon of it on the NASC auction for $15 bucks ($10 cheaper than what I usually sell for via PM). Not only that, but I *think* my bag weighed three pounds, not two like in that auction. I REALLY cram it in there, while the seller looks like he fluffs it up a bit. Maybe Macamus3 can tell you of the quality of what he won
The bog was sprayed with an herbicide to kill weeds, but it looks like the Sphagnum is coming back. I should have plenty this year for the NASC auction. I suggest you pass on that joke on Ebay and wait until I can provide the forum members with the real deal in the next NASC auction. Assuming it comes back in quantity by then (It looks like it will.)
Here's an old picture of some of the stuff from the bog in front of your cabin. The moss I send out is always (except for that one time mentioned above) of this quality. I'm not saying get it from me lol, I'm just using myself as an example since I am blessed with a natural bog and can send out live Sphagnum often. It's very fast growing, as you'll find out when you get your own
