Quote from nitro:
I used to believe that until I tried to build a machine with a particular chipset and a particular graphics card, with the right number of PCIe x16 slots. I couldn't find a pre-built machine that had those parametes for less then $1.5K, and I can build a similar machine, that is not even available, for about $700 less! [With no OS installed, so really $450 less]
If the machine you are building is just a POC (plain old computer) what you are saying is true. As soon as you deviate even a little from the typical spec, it is worth doing it yourself imo.
To the original poster: It takes an experienced person about an hour to do it right, but can take longer if the case you bought is a real pain to work with. Notice that time is for just putting the components together in the case, not for loading OS etc. No one that I know would do it for less than $65/Hr.
FWIW, I think you should buy the components, and learn to build it yourself. You may make a mistake, but so what? Try again then. It may take you two days to build your first one, but the second one will take waaay less than that. For a beginner, the most important part is to get a case that dismantles every which way, so that you have easy access. That sometimes means an expensive case, but not necessarily so.
The only other tools you need is a screw driver (preferably electric,made to work inside computers, so it has to be smallish) and patience.
nitro