Since early 2014. The last time I had a Core i5-K, Z-series board, 8GB RAM and a mid-high-end single GPU for R10,000 in my System Builder's Guide was early 2H 2012. Towards the end of 2012, that same configuration cost R11k. Then it was R12.5K in early 2013. It stayed at R13k for most of 2H 2013 and went to R14k 1H 2014. 2H 2014 jumped things up to R15k and it's been there ever since.
That's so scary '!!
My system was around 6K for MSI GD65, amd six core, gtx580, 16Gb ddr3-1600 and a Terabyte harddrive