This is "sort" of regret, and mostly because of the extra amount I paid.
I'd put off purchasing a system for a long time - since 2010. The old system finally gave-up (..tick, tick, went the hard disk), but the truth is that I hadn't played any new game on it for several years - always hoping that something significant would come-along. (..The Witcher 2 effectively broke my old computer game-wise, couldn't get more than 20 FPS from it and it often had low's well below 7 FPS.)
Well, at least something (in a certain respect) did "come-along": Skylake and lower power use. Now this isn't to replace a gaming build, but I'd wanted a VM server for several uses, not the least of which was a secure browsing experience that I could keep "on". A 24/7 machine and a machine that I could VNC into (from a tablet and gaming computer) and use without suffering all-manner of maleficent malware on that tablet and gaming system (..or the system colonoscopy of anti-viral programs intending to thwart that malware).
Because this system is of the 24/7 variety, I wanted ECC memory. That of course complicates things.
I could still get an i3 (which supports ECC memory), BUT I had to have a chipset on the motherboard that also supports it. Additionally I needed ECC memory that was supported by the motherboard itself. Skylake processors were slow to market.. so I waited (and after about 3 months they were available near their recommended price from Intel). Then I waited longer for a motherboard, particularly one that wasn't too costly (as in nearing $300). A few more months went by and finally Supermicro had C236 motherboards that could actually be purchased. As far as on-board chip-sets were concerned, I thought that was "it" with respect to ECC. Get a server board and then get compatible memory.
Of course the problem was that this is sort of a "utility" system I'm building here, cost is an issue and while the i3 was about $120, the m-board was almost double that and the memory was more than double that (..for 2 sticks of 16 GB). Still, I didn't foresee any reduction in price any time soon and to some extent I was correct.
While the memory I purchased has gotten cheaper, it hasn't gotten much cheaper. BUT there is one exception now at about only 2/3rds the price I paid.
Worse, about 3 months after making the purchase, m-board manufacturers released C232 m-boards. A chipset I'd never expected, nor one I'd ever heard from a tech source (including Techreport) as being something that will be manufactured with soon.
Long story short: I could have saved about $250 by waiting 3-4 months, and it was a wait I could have put up with.
-I'm just hoping I don't get hosed when I start my gaming-rig build.
On a more cheery note: I don't regret the $245 I paid for my wacom/"surface pro 2" digitizer tablet from China. Ironically it's now a $100 more expensive.
(..the Cube i7 stylus.)