As an L405 owner and enthusiast of this model i can offer you as much advice for FREE as you can take buddy.
My first bit of proper advice would be this: Don't listen to BS off dealers or those who think they know the model well albeit they have never owned one and that is no disrespect to anyone on here before anyone moans. These cars are bloody expensive and complicated.
The early car models 2013/14 cars IMHOP as AN OWNER should be AVOIDED as they were plagued with trouble issues mostly electrical.
The models to go for are the later 2015 onwards. Mine is a 2015 Autobiography 4.4 SDV8 which now has just clocked up 60500 miles with a 100% comprehensive service record from day 1.
I am the second owner too and she is absolutely MINT in every respect and in the near 1 year i have owned her i have already spent £5000 on her in keeping her mint service wise and pre-emptive maintenance wise so if your on a tight budget DONT BUY ONE.
Mine cost £115000 new too as the chap specced her up. He had no trouble in the 6 years he owned her but his service bills were high.
I now use a specialist Range Rover expert local to me and they are bloody brilliant and know these car well as they are both JLR master techs.
Prices vary too according to spec and miles on the clock.
You get what you pay for too.
If you want to know more then PM me and we can chat on the phone.