This was a very good article. I would like to add one thing to the old vs new tech. There are reasons to buy tech that falls across the new to old spectrum. Here's a few examples of items that I buy at different positions on that spectrum. Cutting edge new tech, I in contract to the author tend to buy new PCs,tablets, and phones and here's why: If it is new, the parts supply will last longer and as long as I have parts, I can keep the device going. I don't even consider replacing a device until it is totally beyond my ability to fix or it is over 5 years old. Also, I tend to buy higher performing hardware because even if you can keep the hardware going, if it is being choked by the blotware you still have to replace it. Finally, I avoid in order Apple, Windows, and Android in favour of Linux. All the afore mentioned manufactures push updates to the devices that over time ensure the blotware problem. I suspect it might just be on purpose but have no evidence. Old devices hit the blotware wall sooner than new. However, even though I just recommended new tech for computing devices, don't buy too soon. Let others be the Guinea pigs and find out which phone's battery will catch fire or which PC's capacitors fail within a year.
Hard drives is something that I buy in the middle. Since the purpose of a hard drive is to store data, I want to maximize the storage per dollar of my purchase. So for all the drives I look at I calculate the terabytes/dollar statistic and choose the highest one. What you will find if you do this is that when a new device comes out it is scarce because it is just starting to be manufactured and it has a certain 'shiny new' which drives its price up. At the end of the products life span, it is again scarce because it is out of production. However, right in the middle is a sweet spot where it is being produced in large numbers and it is not the shiny new thing where the capacity per cost is maximized. This is where I like to buy some things.
I can't really think of an example of old items I like to buy. In general, sometimes its good to wait and see what tech is going to be around for a while before you buy in. Think VHS-Beta or Zip Drives-Flash Drives.
Finally, I did resteem this because this whole article is something I could have written with very little exception. There is a lot of good advice that only comes from experience here and it is nice to see it codified in one spot.