The two I've had the best luck at are the Fair lakes and Gaithersburg locations. The Potomac Mills location has a lot of nice Talbott ties in the 30 dollar range also good prices on the summer weight slacks. The Neimans, and Saks there are so-so much better at the Arundle Mills location.
I've never known black on black to be typical evening wear, more like club wear in my opinion. If a suit is all that's required consider a white shirt and a decent tie. If it must be black tie and the black pin stripe suit is all you have then a white shirt and a black bow tie would have to do,
Often for the convenience, or some are more into labels then personalized fit. Often wealthy people rather take a off the rack suit get it tailored and have a suit with decent materials and construction without the drawn out process that can sometimes occur with bespoke.