Owning a computer is much more affordable now than it was in the past. In the earlier years, a computer generally set you back around $2,500 or more, a lot of money for a hobby. For a long time that price was constant except that, as technology moved forward, you got a more powerful computer for your money. Eventually, as competition became more intense, the price inched downward. I remember what a huge deal it was when the cost of a new computer broke the $1,000 barrier.
I built my first computer in 1985. I went to a "Computer Show" where there were many vendors selling components. I bought all the components at the show to build a clone of an IBM XT. I don't recall the exact total that I spent that day, but it was around $1,500. I do remember that I paid $500 for a 20M Seagate ST-225 hard drive. The XT clone I built was actually better then the IBM XT since it ran at 8Mhz vs 4.77Mhz and had a 20M hdd where the IBM only came with a 10M hdd. The cost to buy the IBM XT was around $4,000 but I built my XT clone for less than 30% of that.
The point I am trying to get to is that the cost difference between a pre-built and a self-built computer is much smaller today than it was in the past. The main impetus for building a computer today isn't so much that it's much less expensive. It's more for other factors, such as the ability to customize it the way you want, choose the components you want and the satisfaction of doing it yourself. You may be able to build a computer for a little less but not for substantially less as in the past.