Problem solved. Navy blazier no longer fit so we headed off to the mall. After looking really hard, we found a sale on suits - $99 - that was the same as the price of a new blazier.
Teenager thinks he looks cool in black suit - "Men in Black" thing I guess -and mom is happy. We already had belt, shoes, tie, so not out too much money.
I even thought briefly about borrowing a tux from the high school band that he is in. Our top bands perform in tuxes owned by the school and we just turned ours back in for the year, but teenager thinks black suit is far more cool and he can wear it to a family wedding later this summer.
I think deep down the kids really do enjoy the opportunity to dress up, or at least are curious enough to give it a try. Now if I can convince him to cut his hair............