Would never buy a commercial kit. I do sometimes look at the contents list to see if there are any good ideas there.

The process of compiling one's own kit allows for more quality control and also has the advantage of familiarizing one with its contents in a way that buying a pre-assembled may not.

I wouldn't want to give a pre-assembled as a gift because I could not personally vouch for all the contents. So I'm not going to want to rely on it myself, either.