I've sent so many pairs of this exact cut, and style of Levi's back to vendors, I've lost count.  Be it the location they were made it, or what have you.  A 13S seems to mean anything from fitting like a 9S to a 16L, it's ridiculous!  Also, can't beat the 19.99 sale.

**UPDATE**

I ordered two more pairs of these exact jeans, from the exact vendor, who could pass up Levi's for $20?!

They are NOT the same as the first pair I got.  These are better...the first pair I thought were "fine", but they were the soft, almost not denim, denim.  Appeared to be a knockoff, the Levis symbol on the inner tag was solid black, didn't feel like Levis.  The next two pairs I ordered were definitely denim, and had different tags.  Buyer beware!!!