my super cheap first model of a dumbed down version. i'm going to take some more test footage today but my only real issue is a little bit of "sway" in the pitch axis which i'm suspecting is due to the bearings being perfectly lined up. biggest future improvement is going to be upgrading to machined joints instead of PVC so the axes line up squarely on the CG of the camera and there isn't as much play in the joints.
manfrotto 577 quick release system $60
5' - 3/4" aluminum tubing $12
scrap aluminum plate and angle $8
6 pvc 90's $3
3 bearings $9
2 part aluminum epoxy $6
misc hardware $10
without the quick release i would have been under $50, but i'll definitely be using it on other projects so i'm not worried about it.