As far as the weight, I'm not quite sure, maybe 150# total. As far as losing flow, that reducing camlock is from 1.5"-1, so not to much loss.
Now for a rundown on cost; Pump and Motor=200.00
killer deal on that, new P-180 impeller=105.00, T-80=50.00
, complete rebuild kit=130.00
, Floats and header=366.00, aluminum sluice channel=25.00
, riffles 37.50, steel for frame=25.00, camlock fittings=50.00, nozzle=51.00
,pressure hose(intake)=15.00,(discharge)=30.00, suction hose(4"x15')=110.00, hose clamps=35.00, rubber and misc. hardware=50.00. My time and effort= PRICELESS.
4" Dredge with air=1280.00, I rounded up 0.50 cents. All I can say is that if you are patient and do your research, it's not that hard to build something yourself.