You are not the first retailer from whom I have heard such comments.The mention of 3 piece suits reminds me of the mid 60's when Chipp ran a range of 3 piece suits on the rack. At the end of the season we had about 70 vests that suit buyers left behind in spite of having paid for them.
For myself, I like three-piece suits, both with single and double-breasted waistcoats. I was at Ralph Lauren's mansion at 72nd and Madison recently, and he has, RTW, a navy windowpane double-breasted three-piece suit, with a double-breasted waistcoat. The waistcoat was quite handsome, but fit me like the skin on a sausage, as opposed to the jacket, which fit quite well and comfortably, but overall, the effect was rather odd - all beautiful pieces, but one cannot see the waistcoat when the jacket is buttoned, and wearing a double-breasted jacket open may take a bit more bravado that I am normally able to muster.
Now, if the suit remains on the rack, and gets marked down seriously this spring, maybe I'll pull the trigger - a misplaced sense of thrift can cause better judgment to be seriously clouded .