Trouble with central locking Clio 2 Phase 2

My problem is the ZV in my Clio 2, with a 1.2 l 16V engine and 55kw. Sometimes I have to press around on the key a dozen times before the Clio opens, I take the spare key immediately, but sometimes also after the xth attempt. Then for days again everything works perfectly, then it works immediately. I was already with Renault but… The master there told me that he had to go there once again. f Troubleshooting could take 1 hour or even much more (pay per hour 82,60), it could be a small mistake that doesn’t cost much, but also something really expensive. He recommends me a new engine control unit, as well as a new ignition lock with 2 new keys, cost incl. working hours 834,78€ Is there perhaps another alternative? My Clio is almost 18 years old, I bought the 5 years ago cheaply and only last month without defects about the TÜV cht. Mürd me over help happy greeting Mike