sell a GPu without box

Hi I currently have an ASUS Radeon HD 6990 4Gb (2 x 2Gb) that I am maybe looking to sell the card, I just want to know how much more or less it would go for, and as I am in South Africa please (if possible) give me a price value in ZAR. It is quite an old GPU but it still works with no issues...

I plan on building a PC in late June early July. I have a list but I'd like a confirmation, recommendations, or even builds. So what I need/want: My budget is around $1000 I want a PC for gaming and light video editing for YouTube and I even plan on streaming a little. I want this to be a...