Proper etiquette would've been to wait for a reply to a deal YOU initiated. If it were too much "hassle" to work a trade versus a direct sale, why did YOU tender the offer?
As for "serious interest", may I remind you I had expressed "serious interest" before the previous buyer backed out.
Being fair to everyone would've involved you either withdrawing your trade offer to me, or honoring it; your choice.
I'll say no more on the issues.
Ride safe, ride often, but do ride.
__________________
My bikes: '81 Trek 957, '83 Trek 720, '85 Trek 500, '85 Trek 770, '81 Merckx, '85 Centurion Cinelli, '85 Raleigh Portage, '92 RB-2, '09 Bianchi