Always put a used pump ina barrell of water, run it, check the running amps as you close a valve to zero flow, then record the maximum pressure made. try it half shut and pressure at say 50 psi and measure the outflow in GPM. Now you know something.
Wise decision! I have several 1/2 hp submersables that I would love to get $75.00 each. They worked when we pulled them and could last for years or they could die tomorrow!