A.IBM Memory is tested and supported in IBM systems， plus it automatically assumes the balance of system warranty. It is much more difficult to sell memory upgrades to customers after the server has been purchased.
B.IBM memory is no different to third party memory， so memory can be sold at any time after the sale with ease.
C.IBM memory needs a ServicePac to be sold for warranty to be implemented， so can only be sold at time of system sale.
D.You should sell IBM memory at the time of system sale， as Servers can not be expanded once configured in SSCT.