when car misfires can the spark plugs just be changed

What is your question?

put on meter car was misfiring on 2 cylinders 2 & 4 took it to shop they drove it then put on there meter said all were misfiring (car never stalls only runs a bit rough first thing in am) said we need to replace the injectors $700 +. i want to know can the spark plugs be replace and some how blow out the injectors? because if they change only the injectors wont the plugs need to be changed also.? add that to the $700 and I become the next person to be forced into public transportation i am a single person a senior just barely but that is way out of my price range can someone give me some guidelines