That price is about $30 cheaper than the same uni on UDC. I would make sure that it’s ISIS, but if it is then it’s a good deal. The item number didn’t change when they went to ISIS on this uni, and so they might be using the new description for the older square taper version. You might want to call them to be sure before you order it to confirm that it’s ISIS.
If it’s really ISIS then the cranks have splines which will make them better than if they didn’t. The good thing about it is that if you need stronger cranks later on you could get Nimbus Venture’s, or Kris Holm Moment’s. They will go right onto the nimbus ISIS hub.
If this is ISIS, I think you have found probably the best price on a decent uni. If you find better prices, they will be for inferior uni’s. The next best bet in a cheaper model would be a Torker LX, and it would be a fairly big step down for only a little money saved. The LX has a less comfortable seat, and a square taper crankset. The seat mount on the LX is unique to that uni, and Miyata. If you decide at some point to get a more comfortable saddle you will also have to get a new seatpost. The Nimbus uses standard sizes, and mounts; therefore, you won’t have a hard time if you need to replace, or upgrade parts later.
ISIS is the interface where the crank attaches to the hub. The older standard is square taper, and is not up to the kind of abuse a uni crank can get. Venture’s and Moment’s are better cranks that will take quite a bit of abuse (moment’s are almost indestructable) and you can see them on Unicycle.com.
I know very well that hubs and ISIS aren’t everything. I am very happy with square taper on my nightrider. I was trying to say that for a little more than the cost of an LX you could have a uni with a stronger hub, and a better seat. In my opinion the seat is probably the more important of the two, but the truth is that it’s not a lot more to pay for a nicer uni all around. You are probably right that this is what it’s worth, but the same uni is offered on UDC for a fair bit more, and I am under the impression that people buy them at that price. This last point makes it a pretty good deal, as long as shipping doesn’t kill the price.