Here is my current build: https://imgur.com/a/gjTaHKO

1. My buddy is selling me this card https://www.newegg.com/Product/Product.aspx?Item=N82E16814126111&ignorebbr=1&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-PCPartPicker,%20LLC-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
Will it fit my current build? without having to buy a new mobo or anything?

2. What would be a fair selling price for my current graphics card?

It will fit the motherboard, don't know about your case. The PSU has the right connectors. Just need the length of the card and the space in the case.

For you vid card... look it up on PCpartpicker, take 1/2 the retail price and hope for the best.

Heres my case: https://www.corsair.com/us/en/Categories/Products/Cases/Carbide-Series%E2%84%A2-500R-White-Mid-Tower-Case/p/CC-9011013-WW

As far as the gfx card goes. it doesnt have a price on pcpartpicker.

How much you paying
For 1070

150, for that one i posted.

hes a good friend of mine who just upgraded to 1080 TI so cutting me a good deal

Dont tell him
Resell it and get 1180
Boom goes the dynamite

I was actually thinking about selling it + my current one to get a 1080

but he knows the price of the 1070, just wanted some quick cash over it collecting dust. type of guy he is.

Well put his Weiner
In your cock holster
Sell it now
Save cash for 1180
Stop being so beta

lul

what about question #2?

probably 150