It's due to the material used // number of sales possible // time and money invested to even break even. When you visit the field how many do you see? How many variations of the "Ugly Stick" do you see? Interest in pattern has diminished (at least in the region I fly in) with more people flying IMAC. The magazines are full of Extras / Edges / Caps / Sukhois. Pattern planes in the ads are in the .60 to .90 size and most are flown as sport models. The scale aerobatic planes have more interest to the average pilot than a purpose built pattern plane. Bill