Obviously leasing and racking up the miles is terrible. If you can't buy out or choose not to you get absolutely ripped. This is why we keep miles in check on the lease even though we plan to buy out. If life happens and we can't buy out we lose nothing.
Amortization and/or depreciation schedule. Look it up some time.
We finance our equipment at work for 7-15 years depending if it ranges from $100k to $2mil. If its more expensive than that allows then we lease. Same same... Time is not a negative factor.