The first design that comes to mind is the Solution. It is steel construction, but other than that it matches your requirements pretty well. As I recall, it is 48' long.
Hull shape is simple douple-ended built from flat panels.
Think of a huge Teal. Rig is two-masted. It is an all-out economy design which is the only way you are going to make your budget. The AS-29 and Loose Moose meet the requirements to various degrees, but you know about them and apparently they do not appeal. It was also designed with economy as a first priority.