If the pump still work, you can spend about $500 to get a quality 5hp motor and starter. Those SB-705 clone are still consider above average in performance. A brand new, equivalent performance and design, will cost you at least $1500.
Keep in mind that the pump itself is 200lbs+ and it's extremely difficult to handle w/o crane or hoist. For home owners, I try to push people away from SB or Quincy and go for a Champion pump.