Steering servo- oil leaking

I have a disco TDI 300 96 model which suddenly has developed a serious leak in the servo for the steering. It looks like it is coming from the oil pump itself.
The leakages is emptying the system over night.
To exchange the pump will set me back USD 5000 they say in the garage-
The pump in UK costs £80-90
Is this something I should embark on myself? Or could there only be a gasket blown? I have checked the piping but cannot find any problem.

I have v8 but i think is usual problem in the discovery therefore, it could be headache. I asked the mechanic to chick it. the problem was the pips it been replaced but the leak starts again. i did chick it my self it is leaking from reservoir connection's to the pipe. i cut the edge of the pipe and concocted it again but no use because the ring clip is bad i replace it with stronger ring clips it stopped like magic till today it also leaks from the pump side too so you need to do it as well.

It's not a big job to replace it.... get a new one and DIY ..e'g Land Rover Discovery 300 Tdi Power Steering Pump | eBay