How expensive is maintenance on a 04 Range Rover? ?

I heard that oil changes, tires, and parts are expensive compared to that of a Tahoe or Expedition. I can get an 04 Range with 43k miles for about $22k. I need some feedback.How expensive is maintenance on a 04 Range Rover? ?
The maintenance, repairs and parts will make a grow man cry because I have several customers that always ask the same question...';can you get the parts in an aftermarket brand';...and sometimes I can but most of the time I cannot...



The alternator is very difficult to find and if I cannot find one then it runs around $875.00 from the dealer.....just an example.