Motorhome gearbox issues

[Kingy58]

Hi good people. I'm hoping this is the right place to come for help.
I very recently bought a Motorhome (privately, unfortunately) built on a 2009 Renault Master chassis with Piloted gearbox. On our first outing on arrival at our campsite we had a major gearbox failure resulting in the vehicle refusing to engage reverse and then subsequently any gear.
The vehicle was recovered to the only place (Renault aside) who could accommodate a Motorhome and they told me I needed the clutch replacing and the gearbox actuator/selector robot repairing and also recommended gearbox bearing replacement while the box was out. The total bill inc parts and labour was £3800.
I have no idea if this was genuinely what needed doing but as I was not in a position to 'shop around' I had no alternative.
My question is that I have a colleague who has similar issues with his motorhome and I would like to save him paying a King's ransom if it isn't necessary.

[dave]

I have a business friend, who claims the Renault commercial dealer is allegedly no-dearer than an independent garage.

Higher hourly rate but less hours on the bill when doing major jobs like replacing a gear box.

Runs a mixed fleet of Maxi Mover vans