Yeah, that's a terrible price, but I recommend you steer clear of Alibaba unless you like gambling and/or don't mind waiting 6-8 weeks to find out if what was shown on the website and what you get remotely the same thing. If you want to take a swing on cheap boxes from China at least get them from fleabay using paypal.
Otherwise, two enclosure manufacturers (in the US) I can recommend are Polycase (plastic) and Lansing Instrument (extruded aluminum).