Approximate cost breakdown:

1) Two 6" F5 Mirrors from Agenaastro ~$290
2) Upper 28 mm secondary ~$15
3) Lower 55mm secondary ~ $25
4) Two 3D printed helical focusers ~$1 (for 3D filament)
5) Aluminum frame ~ $35
6) General hardware: Vinyl light covers, velvet sheets, glue, nuts&bolts, 3D filament, etc, ~$45
7) Two 20mm Celestron eyepieces $40

Total cost of Ultra Light (5Kg) 150mm Binoscope ~$450