Help! Medela Swing Maxi double electric pump or Freestyle

Kelly • First baby on the way after 4 yrs of trying 😍

I am on budget but would like to know which would be better in a long run for breastfeeding. Should i buy a medela maxi double electric or freestyle. Can you tell the difference between these two? I am going to work after 2 mos of maternity leave and will be pumping at work. I saw a second hand medela maxi and plan to use the motor only and buy all new accessories. Any advise pls.