A standard IBM "gotcha" is to offer deep discounts and charge the 20% p.a. maint cost on the list price - e.g. "We'll give you this hardware for $1." then a year later "So sorry the maint is 3 x $250k x 0.2 = $150k p.a.".

Another is that the software and hardware designed to turn a baby system into anything useful is astonishingly expensive to people not used to dealing with this end of the market. Enjoy finding that your hypervisor is licensed at 5 figures per core, and that your cores are six figures a pop.