3 IRT fails is a pity. He should have done the syllabus, picked up the 170A form completed, and then privately rented a freelance IRI to "get good" with, and then (when happy) booked himself an IRT directly with the CAA.
My IR conversion took 32hrs (partly due to a break in training which cost a fair bit of currency, and some other hassles, and I then flew quite a lot with a freelance instructor to be really sure) and the costs were
Ground FTO course material and IR exam signoff (with 3 days' ground school) £1020
Online QB £13
CAA IR Exams £476
Training (instructor charge only) £2000
Approaches £350
CAA IR Aircraft Approval and IR Test fee £962
Adding the IR to the licence £87
On top of that was the cost of flying in my aircraft - another £2500 or so, but I fly regularly for currency anyway so don't think that should be counted anywhere near fully.
IOW, credits for previous training are worth a good deal less than they appear. That said, the present minimum 50/55hrs is way OTT and it should be almost entirely competence based (as the CBM IR would be if/when it comes).