I was with this mindset. And now realise that I should only buy something that I can fully utilise now (true for most of the computer stuff). e.g. SSD, if I pay too much for further proof, most likely I end up pay for nothing. Because the future SSD should be cheaper and perform better. This is especially true if you want to buy the top product. e.g. How much you have to pay for a TitanX when it was introduced? And now, how much the 10xx card cost?
Also, the computer parts become obsolete not necessary because of it's performance, but may be it's function, connector, etc. e.g. If the new SSD in 2017 has some functions that can replace TRIM, the current SSD can become obsolete because just lack of that function, but not the speed.
This is just like the XEON lack of QuickSync, graphic card lack of H265 support / HDMI 2.0, etc. That's not about it's raw performance, but something else.
I am not saying your purchase is not good. I just want to share my point of view now. In fact, I used to pay more for something that I don't really need. e.g. I buy the W3690 but not the W3680. I buy the 128G iPhone but I never use more than 64G. TBH, I paid the extra most likely end up is just to keep myself happy (and my happiness is priceless)