In Aussie ,insurance is the big killer but of course if you do plenty of hours this will cut the hourly rate down.
I enquired on an R22 and it was 15% of value(insured amount)
Have a friend with a Cessna 172 and his is 1% of value.
Think current training rate around $350aus--solo$300
2200 hour rebuild-------$175,000.
Plus being an import exchange rates stuff around the purchase prices.Years ago you could get one for the eqivelant of $200,00 ,then over the last few years it rose to $300,000 as the yank $ rose and the Aussie $ went down.Now hopefully saving a bit now things are reversing.
All the operating costs etc seem way short of an hourly hire rate ,but a lot of unforseen replacements may be needed.If you have a good run you make a good profit.
Also lease costs or if you brought outright (can earn a few bob with $300 grand invested)
Depreciation ,although this wouldnt be too much over its lifetime.
As for doors etc ,tell me a spare part place that doent rip you off,especially if their factory ones.
ever bought a wiper blade for a BMW or similar to find its made by same mob that is on a ford except its 10 times the price.Thats more names sake though instead of limited prodution