Like many hero/legendary members here, you seem to suffer from a superiority complex. Go and see a shrink and please get your head examined. There are so many delusional folks on the forum, it's not even funny.
I bet most people, who are interested in bitcoin, know how to build a pc from parts.
As in life, you get what you pay for in mining. If you use scrap parts to build a pc, you will end up with a scrap pc, it will function as a miner but it won't be efficient and will cost you in the long run. At worst, it will be a fire hazard. Please get a pc built for mining and don't cut corners. Even if you know how to build a pc from scrap parts, a mining pc is not the brightest idea to do so.
LMAO,yes I am delusional
I have 6 "scrap" PC's built & running 24/7 for the last 4 years........they have made 100's of dollars (if not 1000's) for me & are no more at risk of a fire hazard than your brain catching fire
And yes I AM better than you
BTW,the 380 4gig ($150-200) or the 390 8gig ($200-275) cards are the way to go,find em on sale & they can earn that back as fast as 2 months or so
I agree with leowonderful,DO NOT buy used GPU's,I have & regretted it,the return of GPU's on ebay wasted time & a 15% restock fee was a pisser
All other parts,CPU,mobo,ram,HDD,dvd/cd rom,even PSU if of sufficient power (no less than 600 watt),are ok in used condition
BTW,you can resell a new GPU after mining for several months for damn near what you paid for it & the warranties are MUCH easier to get than on any ASIC miner