I've got a PC of which the PSU, case, fans, GPU and HDD are over 6 years old (at least). Motherboard, CPU and RAM are fairly new (2 years old), since the old ones (also over 6 years old) were replaced after the motherboard they were on stopped working due to an electric spike (got a motherboard with a new socket). I want to upgrade this PC and would like to do it with the lowest possible amount, preferably over a prolonged time. What would be a decent small budget? Is any of the components here worth keeping on the PC after all upgrades and additions have been made? My focuses are: gaming (almost always NOT cutting-edge 2018 titles), internet browsing (10-35 tabs open) and storage (I frequently search and browse through thousands of unsorted text, image, PDF and video files in a single folder, which is a big nuisance for my dual-boot system, both in W7 and Ubuntu 14.04). Specs are in the attached pic.