My vote would be poor sales. This time of year I scour the local want ads, garage sales CL, etc... for good deals on old kettles. RARELY if ever do I see an 18.5.......I'd estimate 1 in every 20 is an 18.5 in these parts. If the resales are any indication of new sales I can see why they dropped them. I have a 22.5 myself and am really thinking of selling it to grab a 26.5" as my go to grill/smoker. Honestly, for a family of 4 doing indirect cooks, I run out of grill space quick on the 22.5, not sure how people manage with the 18.5 personally.