Selling car after replacing injector

[rangor gubbins]

Someone I know is soon to be selling their car (ford diesel, 2012, less than 100K miles) but one of the injectors has just come out.
Ideally all should be replaced but this will cost more than the car is worth. What are your thoughts on replacing just one injector. Do you think the others are likely to be knackered or if one has come out is that likely to be a one off incident and the rest could be fine?

 

[rangor gubbins]

Mondeo by any chance? I had 2 injectors replaced at about 115k miles on one I had many moons ago. The 2 originals ran fine for another 30k or so before they needed replacing as well. It's not a case of if, but when. However if the remaining injectors are ok then I don't see any need to replace them immediately as they won't cause any harm, or stop you driving. The symptoms start early when the injectors start having issues, and they're easy to spot.

Just be aware that they will need replacing/reconditioning at some point.

Thanks for the replies @JonRGV250 and @GravyMonster .
Makes sense.
I guess anyone who buys the car will see the maintenance record and realise the other injectors will need replacing at some point.
What about using refurbished or secondhand injectors? Doesn't seem like a good idea to me, and I certainly wouldn't do that to my own car, but I don't know anything about how they work and how they go wrong.
The roadside mechanic who looked at the car said the injector had "popped out" rather than gone wrong. Black smoke was pouring out of the engine.

 

[rangor gubbins]

Might see if the garage can get the original one back in, or stick a refurb one in.