I bought a Mantis Valkyrie on eBay a little over a year ago.
Since then, whenever I do a search for Mantis Valkyrie, I see the eBay auction pic of MY BIKE all over alibaba and ali express from many different sellers for many different bargain prices, all of them about a third of what I paid. Just do a google search for the following:
mantis valkyrie ali express
Here's one of the links from the google search:http://www.aliexpress.com/reviews/18-stay-reviews.html
Would I buy from them?
In a word,
My advice: http://www.youtube.com/watch?v=KAp9sFVdERQ
I suspect the reason they post that listing of my bike is nothing more than a way to draw you in to their shop; the ol' "bait & switch", which is illegal in most places except for (you guessed it) China.
Check out this screenshot from the above link. Note that they all include the original seller's misspelling ("MOUTAIN").
Life! Life, do you hear me?! Give my creation LI-I-IFE!