It probably depends upon the context. It is certainly more difficult to build a run of the mill system than clicking boxes on a website then unpacking a box when it arrives.

On the other hand, it is usually easier to build if you know what you're willing to pay for and which corners you are willing to cut. You just create a list of what you want, order the components, and put it together. (If you don't want to spend an hour putting it together and a couple of hours installing software, the vendor will usually do it for you.) In the case of pre-built systems, you are stuck with the vendor's offerings and expensive build-to-order options. Couple that with vendors providing incomplete specifications on their systems, and the research quickly becomes arduous.