No one argues that 48 months is an unreasonable mannequin life time. And when you spend your budget, you need to get the expected return on your investment.
But the return on investment, comes in the form of clothing sales, that’s why the mannequins actually need to be doing their job. Which is to be ‘present’ in the window or on the floor (aka not in the store room, broken) and they need to do your fashion justice (aka they can’t be scratched, broken or unsightly).
We’ve seen the cost of not having a plan being triple to quadruple more expensive than having mannequins with the 4 year life & day-1 condition guarantee. This is not a small or marginal difference.