I went to one of our shops and picked up a 3/4 ton ford drum for free. All the pipe is leftover well drillng pipe from the legs for my welding table. Didn't need any fittings I cut and welded the tee for the blower and on the bottom for a clean out I'm going to weld a bolt on the pipe for a door to swing across the bottom of the pipe. So far my investment is some C25 gas, welding wire and about an hour of work. Need to go out behind the barn and search up some 1/4in plate to put in the bottom.
I've been doing welded ornamental iron, jeep roof racks, bumpers and such as side job for a few years so I have a pretty good stock of light gauge square tube and angle iron. So legs and frames will fall into the free range too.