I bought computer components during a Mercury rx because our taxes were just about to be raised so I rushed in. However, I had to replace two faulty components out of the box, and the retailer gave me a fuzz about it. Fortunately, consumers rights are well regulated here, I just had to insists with the correct words and eventually got my replacements, but it took 2+ weeks and unnecessary hurdles.
If you can avoid this, then it is generally advised to avoid. Notable exceptions always occur, of course (there can be many reasons)...