Cambelt change every 40k is overkill on these engines. Even VW revised that interval to 60k. Take your chances with the 4 years.
Personally one cambelt change on a 71k engine, I’d be happy with that and wouldn’t see any urgency in getting it done just yet. Many of these motors have exceeded that without a single change. Just factor it into the cost if you’re serious.
I think some people have unrealistic expectations when buying 2nd hand sometimes, and expect them factory fresh. But the fact is it’s a 12 year old car now. Unless you’re buying from an enthusiast, you will need to spend money somewhere, it’s almost guaranteed.
Best of luck