I really can't imagine that cost is a factor... it has to cost more to support a mainframe environment (especially assuming the need for a raised-floor, Halon-p

I really can't imagine that cost is a factor... it has to cost more to support a mainframe environment (especially assuming the need for a raised-floor, Halon-protected, chilled computer room and oversized, power-hungry peripherals) in anything but the shortest term.