As a long time owner of one of the oldest L322s I can only say one thing and it is not meant as an insult, "if you have to ask about cost you cannot afford it".
If you have £40 -45k to spend , reckon on 30 -35 for a Range Rover and keep the rest for what may, can, will need fixing. No matter which model you buy.
Range Rovers are the gift that likes to keep on costing. Dealerships class anything over 4yr old as 'old' and although they may sell them they are not interested in maintenance. Which leaves the search for a good independant. The cost of parts
never goes down, unlike other marques. In fact most parts stay with market increases. £300ish for wing mirror glass for my L322. I don't have the courage to look at the price for the same part on a newer model
If however you have fallen in love with a particular model, but accept that it will never love you the way a Volvo will and will never get less expensive to run like other marques, then the cost of unrequited love can be worth it.
P.s stay away from electric. You lose space. Especially leg room. I had a weekend test drive in a lwb about 5yrs ago. Less boot space and less leg room than my L322.