At my last job, we made several manufacturers tender for our complete hardware supply contract as well as provide loaners of each of the major cateogories (laptops, desktops, projectors, tablet PCs, servers). Lowest cost didn't end up the winner, we went for a combination of value for money, service and the quality of account management. Dell came out as a clear winner, but by the time I left we'd been through several changes of account manager/executive and response times and willingness to help us out had suffered as a result.
New workplace is all Dell and so far we've had no dramas.
