I recommend to never go to the dealer, unless you're going there for a warranty or recall repair. A local repair shop is always the better option. And if you don't know of a trustworthy local shop, take it to the dealer for an estimate, and then you know if the local shops are bullshitting you (they should come in way under dealer prices).
Even within an organization, creating externalities from one department's perspective seems common enough.
Even if a decision maker is aware of the possibility of externalities and cares about a broader constituency (temporal or "spatial"), evaluating actual costs is an expense as is justifying that investigation expense and any mitigation/avoidance expenses to others in the decision web.