I don't have an Saint Laurent stuff, but I can tell you W+H quality is good. Generally nice fabrics, good construction, details like buffalo horn buttons and riri zippers. A lot of SLP would be paying for the design and brand.
Based on my experience... My order from End was marked as the order price. My order from Oki-Ni, however, was marked at full retail and resulted in me being charged a 20% customs fee on that full retail.