Repair costs

Hello together I’m just hanging on to the purchase of a G. Now that the garage fits and the rust theme seems manageable, the ongoing maintenance costs are driving me around. Mercedes offers warranty extensions for 1,000 Euro pa. If one then subordinates “normal” inspection costs of 1,500 Euro then “unplanned” costs of at least 1,500 Euro will be added (otherwise the extension of 1,000 would not be worthwhile for Mercedes). Is this possible? How are your experiences? (will a G500, new, then flooded with Mike Sander)