So the cello from 2016 is the one you prefer to play? Do you own that one too, or do you have it on trial? From a financial perspective, you have a german trade cello that you don't really like to play and an expert has told you it needs a new neck. It's might have other problems, like a top that needs to be regraduated. Ask your expert about that and get a quote on the value of the instrument and compare that to all the possible restoration costs and the cost of a new cello that you like. If there are other luthiers in your area, or within reasonable distance, don't be shy about getting other opinions before you decide.