baby shower problems

I'm pregnant with my third....my kids are older. I told my family years ago we're done having kids but we changed our minds...we thought we were done so we got rid of everything 😥 my family says is only appropriate to have 1 baby shower and because I have one of each gender already I shouldn't have one. What things should I avoid getting second hand? I would buy brand new a crib, mattress, car seat but the rest I'm thinking used.