Agreed with wonder_guy, a good b16 is really hard to find these days, secondly parts are not readily available for b-series. D-series is recommended.
still following are the prices;
d15b single vtec (45k to 50k) complete setup along with all work
d15b dual vtec (50k to 60k) complete setup along with all work
b16a (80k to 110k) depends on condition and exact variant of b16a series
b16b (No idea, very rare, never heard any one having a b16b in pakistan)