If you are looking at the low-end price range (i.e. under $300-350), it’s not necessarily a good idea to build it your self.  You should either save up for a $500+ PC (if you plan to use it for heavy-duty tasks) or simply a cheap little prebuilt machine if you are primarily using it for basic tasks like web browsing, Youtube, Microsoft Office and Skype.   

The cost of building a PC is not always proportional to its performance.  PC’s have a variety of different parts they require and an overall cost minimum.  Whether a computer is very low end or mid range it will require a power supply, motherboard, case, etc.  So, you may as well pay a bit more to get the most out of these parts if you choose to build yourself.  A $350-450 computer build is definitely possible, but you won’t have a wide variety of choices at your discretion either.

Over $450-500, it does make sense to build it on your own.  If you want a PC for a specific specialized purpose such as 3D engineering, professional photo editing, music production, professional video editing and gaming, sure.  Prebuilt PC’s over $500 are not terrible, but they do use a lot of cheap parts and they charge a markup profit.  They’re just overpriced for what they are.  Many of the pre-built gaming PC’s for $800 have the kind of video card you would expect from a $500-600 machine you could build yourself.

Building a PC is easier than it may seem.  The hardest part is deciding on a part list and ordering the parts.  In hindsight, I probably could’ve saved a lot of hassle just by taking a build list from a reputable Youtuber like Paul’s Hardware and tweaked it a little bit for my own needs rather than spending too much time debating on the many details of parts.  Aside from ordering parts, building a PC is literally just connecting 20 cables to a motherboard.  It’s more like solving a small jigsaw puzzle than performing surgery.

Is it worth your time? 

Now, that is a reasonable question.  For myself, absolutely.  I enjoy tech and I saw the time I spent building my first computer as an investment in learning a skill. 

However, for someone who isn’t interested in tech and just wants a good PC, maybe it is worth spending the extra money on a prebuilt.  Although, if your budget is in the mid-high range, such as $600-1000+, you should probably pay a friend or a small business to do it.

UPDATE (Feb 2018)

The significantly increased prices of video cards due to the cryptocurrency mining industry buying out many of the cards has re-opened this discussion.  The price of pre-builts have not been impacted (at least yet).  Although building is most cost effective overall, if it’s cheaper to buy a pre-built with all of the same features you want, you may want to go the pre-built route, unless you really enjoy building.