Hi Les,
I recently had one with intermittent non start. When it wouldn't start the fuel pressure was lower than 1 bar and when it would it was over 2. Once started it ran fine. The front pump was very noisy so I scoped the current draw and found it all over the place. With this evidence I replaced that pump without even looking at the intank pump which turned out to be a mistake as that one wasn't working at all. The new pump was quiet and the current trace was now stable so I did feel that the pump was indeed on its way out and was justified in leaving it on the vehicle and charging for it. With regard to your problem I can tell you that this vehicle ran very well once started with just the front pump only half working IYSWIM. I can't recall exactly but I think the cranking pressure after replacing both pumps was about 3-4 bar.
Regards,
Bryan.
PS. I think fuel filters are also very common, even at low mileage, and I have changed these for fuel pressure problems in the past.