Somewhere between 3000-5000 probably.
I can either rebuild it or replace it with a second hand one (if found). Replacing is marginally cheaper but not the best long term solution. Looking to see if I can convince a dealer to accept is as trade in (at a much lower value obviously) if I spend more on one of their cars instead of looking for something cheaper privately (I cbb selling mine privately any more). I have told the dealer principal that I've influenced family + friends to buy Golf's, some from his dealership. He seemed nice enough and asked me to bring it in for their own diagnosis but I reckon he's more curious to check it out rather than be of great assistance to me. Some have had 'good will' repairs performed for this common issue at reduced cost (free parts, pay for labour).
The best financial outcome I can imagine is pushing for a ~$1800 good will repair then sell privately for a low ball price. We've got a 'spare' Mk4 Golf 1.6 Manual in the driveway I can use (my sister used to own it before buying her Mk7) + I've got the motorbike.
Thanks for the bro hug.