1970s 4 bed semi rewire price expectation

€10K give or take

It all depends on what you consider a complete rewire. If you are moving sockets and lights as well as adding extras in it will be fairy expensive. Moving lights and sockets downstairs can mean taking down ceilings. You are then into plastering and painting costs

Anything from 10-25k depending on what you want done and where in the country you are