I could buy it cheaper
Works fine as long as you support it as well for the lifetime of the kit.
You will have a budget for that next year, won't you? Including software licences?
Oh, once you have bought it out of the petty cash it is ITs job to support it for the next five years?
Talk to me again about how much money you are saving the business!
Been there, suffered that, cheap deal always wins over TCO then its SEP.