I wouldn't count on them being authentic especially if they are coming from China. I see mass amounts of BCBG, Lacoste, even Abercrombie and Hollister items which I think are even fakes since there is so much of the same item new with tags.
Those are super cute shoes thuogh. I'd get them if the price was good, but not real Marc Jacobs price. Also hard to say if those are the actual shoe you would be getting or cheap looking knockoff. I'd look at their feedback and check to see if they accept returns.