Multicore has been 'for the masses' for a decade or more by now, even in mobile phones. What is different here than with other chips made by Intel or AMD that makes you say that?
Intel's offerings with more than 4 cores have been segregated into an "enthusiast"/HEDT platform (X99) with more expensive mainboards and the CPUs have been overpriced too.
Ryzen is reasonably priced & has one socket for the 4, 8 and 6 core CPUs.
If anything Intel quad-cores have been regressing in the market over the past few years. The quad-cores have gotten more expensive (in laptops), and Intel has started naming dual-core chips "Core i7", as another trick to charge almost the same prices it charges for quad-cores.
Which has been a bad move in the desktop market. Who want's to pay for integrated graphics when they are just going to put one or more discreet GPUs in their system?
The only reason LGA 1151 has been so successful is that most of the market consists of "gamers" who are convinced that they need higher clock speed and IPC.
AM4 should only be compared to LGA 2011v3, which has a very inflated price.
Intel's multicore CPUs (hexa-core and octa-core chips) have been available for for Intel's socket B/R systems, which are the HEDT grade. These systems came with a price premium, which isn't exactly the case for R5 and even R7 builds.
Currently my home 'workstation' is running a x5670@4Ghz, a 6C12T Westmere xeon from 2010, but it still competitive and can be bought for peanuts today (bought mine for 70£). Its base clock is 2.95Ghz, but it easily overclocks to 4Ghz and beyond.
Since TDP is not power consumption, the GTX 1070 will most likely consume less power than your CPU because it has much better power saving features.
Also, since CPU's are idle more of the time than under load the savings by using a newer CPU like Kaby Lake or Ryzen could be interesting. There is also the motherboard. Newer boards consume less power because the chips are on a smaller node.
But I guess the money you saved on buying the CPU will outweigh the electricity costs even in countries where electricity is expensive.
It might be an issue, but I still got mine (a Gigabyte x58A-UD3) for 140£. I was specifically looking for a MB with decent overclocking support and working VT-d, which limits the choice. You can get entry level x58 Intel MBs for much less (overclocking these xeons only requires bumping the BCKL to 200Mhz and maybe bumping the core voltage a bit, nothing fancy). The RAM is also still fairly cheap.
If you care more about core counts than single thread clock you can find used x58 dual socket workstation MBs which also have support for large amounts of server ECC ram which is very cheap.
