I bought a 08 HR Navigator 18 months ago and have put 10K miles on it. Other than 2 new from tires ($1300) most of the following are upgrades..,were not necessary.
$700...3 new LED TVs (2 smart TVs)
$1000..Silverleaf monitor system.
$700...2nd basement slideout tray
$1200..900W DIY solar system wit 80A mppt controller
$550...880AH of AGM batteries (lead/acid were OK)
$300...Induction cook top instead of oven/cooktop... additional storage under
$140...resew all 4 slideout toppers
$120...70+ led bulbs and 2 clearance lights
$60...adjustable mount for the Safe-T-Plus
$55....2 fuel filters and engine oil was changed before buying
$4650 in upgrades, $200 in repairs, and $1300 for 2 new front tires. Did a 6000 mile trip this summer and the fuel filters were the only repair...do not see any major expenses in the next year.