I've been given an estimate for some work and I just want to know if it's reasonable or a rip off ..

1) Both Cross Link valves need replacing.
2) Rear prop shaft (bearing I guess), worn and needs replacement

Two separate jobs, have quote for £400 each (+VAT)

Thanks 2006 Range Rover Sport 4.2 s/c with Arden bodykit

Propshaft is a little pricey

I can count on one hand the amount of valve blocks I have replaced. What is the actual fault with the car?

So with the cross link valves :
The car sags on drivers rear corner over several hours, car tries to re-level itself, corner drops some more over several hours, re-levels, basically repeats and if I haven't used the car in several days then the suspension is right at the bottom all four corners and shows at locked in access mode when I do start it. Pumps up fine when started.
If I remove the air suspension fuse, to see if its a fault in the sensor (something I learned here on the forum), the corner still drops, so it's a leak.
The garage had the car overnight and ran the same and other tests.

With the prop shaft - I don't notice any problems, just something they reported during a service and health check.

Two further questions, along whether the quote is reasonable - is , is it worth doing at all?
The garage says, the air suspension will just cause stress on the compressor and maybe wear that out prematurely,.
And the prop shaft may go next month, or in 50,000 miles, hard to say. 2006 Range Rover Sport 4.2 s/c with Arden bodykit

Before changing the corner valves, they should check the pipes and fittings for leaks. No point spending £200 on valves if there's a simple leak in a pipe. The pipes between the valves and the airbags are at corner pressure so any leak in that pipe will cause the corner to drop. Fixing a leaking pipe could be £20. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Yeah I think they did do that, but will ask. 2006 Range Rover Sport 4.2 s/c with Arden bodykit

What was the outcome?