Well this is the way i look at it, save and build something that will need upgrades in a year or 1.5 years, dont buy something small to upgrade in a few months.
Plus think of it this way, sure you are buying bare bone unit and it will perform but electronics degrade over time, things don't work like they use to at peak.....buying a good computer will LAST a long time and work with upgrades.
It's like a conversation i had with a friend who buys domestic cars and me Japanese, his argument is why would i pay more for a Honda when my dodge neon runs fine, as long as you maintain and take care of the car it will last long, my argument was but how many times do you have to replace parts, how many times do you have to do maintenance (over the regular suggested times)
Also he sold his car and for something else because he noticed issues that will cost him 50% of the value of the car.
Pay more and get more, i push my Honda to the Limit in every way and it gives back, most cars you push just a tad bit and it fails.
Your computer is the same way, get bare done now but when heat becomes and the performance doesn't last as long then you will be spending cash again.