I recently made didgeredoo from plastic water pipe and a mouthpiece that was made with help of 3D printer. For less than 10eur. The reason was excessive size of the pipe hole. So I adjusted the size of pipe to fit my mouth with the help of a mouthpiece. If you have a relatively larger mouth, the mouthpiece is not needed and the price is reduced to 4eur.
I bought the pipe tube in store. Then I draw mouthpiece in SketchUp, very useful and free program for drawing 2D and 3D models. I exported the file to the STL format and went to the 3D print shop.
Because of a relatively large product it took few hours to print the whole model. Result was compact and solid piece. I brushed it and washed and it was ready to put on the hose. For better grip, I put a layer of tape between the tube and the mouthpiece.
About the 3D model: the half of the mouthpiece has a conical opening, the wideness slowly increases from the place where the mouth toward the place where it reaches the inner tube width. The other half, which is placed on the tube, has a constant opening.