I owned an 18 inch one of those that my brother and I both learned to ride on. I’m pretty sure that they come off of an assembly line in china and are sold with different brand names. On ours, we have replaced the cranks, the saddle, the pedals the tire and the tube with only a few hours on it. I would recommend buying a torker, as I have been very happy with the LX and CX that I have. I’ll try to list the advantages of each component, but if there is something that I missed ask me and I will try to answer.
Saddle
Toker CX: If you are older than 10 the saddle on a CX is way to small and terribly uncomfortable.
Torker LX: A pretty good saddle, but not the best.
Chinese: Almost as good as the torker LX while it stays together but mine broke apart and it had to be replaced.
Frame
Toker CX: Flat crown is strong but definitely not as strong as the LX.
Torker LX: Flat crown, seems pretty strong.
Chinese: Round crown, about as good as the CX.
Hub
Toker CX: Square taper, but pretty sturdy.
Torker LX: Square taper, seems the same as the CX.
Chinese: Square taper, probably almost as good as the torker ones.
Spokes
Toker CX: Nice and strong, nothing has gone wrong yet
Torker LX: Nice and strong, so far so good.
Chinese: Not near as good, a few have bent slightly on mine.
Rim
Toker CX: Pretty nice.
Torker LX: Seems very strong
Chinese: Very cheap
Tire/Tube
Toker CX: Good for road
Torker LX: Very nice I think its a kenda k-rad
Chinese: Terrible! I wore the stock tire out in a couple of hours
Pedals
Toker CX: Not particularly sturdy, but not to bad
Torker LX: Sturdy, but I put different ones on mine because the original ones wouldn’t grip my shoe at all
Chinese: About as cheap as pedals can get
Cranks
Toker CX: Cheap steel square tapers
Torker LX: Square taper, sturdy aluminum.
Chinese: Cheap steel square tapers
I think that about covers it, If you want to do hops and drops you should buy a torker. You could buy the CX that the link goes to, and kind of go half way in between the two, but you will probably want to replace the saddle if you do. If you do buy that one off of amazon, it will ride nicely for a while, but from my experience it will start breaking and not stop. I put a link to an LX, that has a best offer. You can probably get it for $130ish.
Wow I’m realizing how long this came out to be, but I think I managed to cover pretty much everything.
Link to cheapest CX
http://www.ebay.com/itm/TORKER-CX-Unistar-24-Unicycle-Bike-Bicycle-Cycling-w-Stand-Chrome-NEW-/221159624142?pt=LH_DefaultDomain_0&hash=item337e240dce
Link to LX
http://www.ebay.com/itm/New-Torker-24-Unicycle-Unistar-LX-Black-Chrome-Bicycle-Stylish-Road-More-Speed-/220956309353?pt=LH_DefaultDomain_0&hash=item337205b769