Half the price of two feet 300mm 12 inches 30.48 cm
300mm is 9.72 x 10-18 parsecs.
300mm is a very low head, you can't expect much flow through that pipe, but you can work it out from the mechanical energy balance equation.
450mm x 300mm 45cm x30cm 1350cm
It is approx 80.4 mm.
30cm
..about 300mm
30cm = 300mm
About 300mm a year
11.8110236
32cm
3 cm.