Hi Avo, first thing this is the regular GTX 780 in the link above and not the TI version, therefore the price is reasonable, second its also available in Amazon you can searh by part number " GV-N780GHZ-3GD", finally you should know that Newegg and Tigerdirect do not accept lebanese credit cards and I have tried myself befoee even called them and spoke with accounting departement they just dont accept.
Also if you are going for the GTX 780 non TI may I suggest the EVGA brand ? I got mine from amazon for 499$ back in 2013 and it did cost me around 90$ for borderlinx (customs - vat - clearing), I have the reference model (Titan look) great card, silent and 3 years warranty.
PS: I have a Corsair CX600 PSU running i5-4670k - corsair h80i cooler, some leds and about 7-8 desktop fans without any problem so I believe your PSU is more than enough.
Oh, how I didn't notice it's not the ti version! :/
So that's why it's cheap.
Also, my relative was gonna use his credit card, not me.

Anyway, I changed my mind.
I will just get the 780ti from pcandparts. I don't want to take any chances.. Especially with my luck in electronic devices that I buy!
It's not the Ghz version, but it will still do.
I liked the backplate of the Ghz version, that's why I had my eyes on it.
If you game at 1080p you'll barely notice the difference between the 780 and 780 Ti unless you're playing Crysis or Metro.