You forgot about the bigger car/wagon/4WD to get out to a decent dark sky site.
Then there is the petrol and wear and tear on the car.
Couple of bucks to clean the car since more than likely there are dirt roads involved.
Then there is the time off work to head out yonder.
Then there is extra storage room to house the scope- may need a bigger house with a bigger mortgage. Wife whinges about "the coffin." Add lawyer fees for the divorce.
Any time for a third job? (hey, don't laugh - my third job's income was specifically dedicated to astro gear, but ths had to be chucked in, as the %^%#@#% kept taking my time put aside to head out stargazing at short notice to book in work - every opportunity last year wound up being torpedoed at the last second

.)
Do not expect to get much time any more to head out to that favourite dark sky site.May have to wait till I retire, but oh, no, my eyesight will probably be shot by then........