Finding a gtx 680m for a cheap price

Yes hello i am a first time poster and have a serios question to which i could not find the answer to on the almighty google. I recently brought a clevo p370em with grx 670ms in sli and the graphics do not stisf me. I would like to grey one gtx 680m or just anything higher then the 670m for a good price not for 800 dollars on upgrade money, and have searched the Internet  But cannot find anything. i need it for a good price and to maybe pay a certain amoun Of money for a certaiteam punt of time. I woul. Also like to cell my 2 670ms to get some money back. Any and all help is greatly appreciate and if one of you guys have a spare one that I could buy and don't mind being paid over a time using pay pal just reply.

So your looking for a 680m, To replace 2 670m's? You do realise you would recive a performance drop unless you got 2 680m's? And even then if you want something that will play games you should go for a desktop? 

Make a desktop. It's WAY cheaper and the graphics are 3 times better easily! Laptops from the ground up are not made for games but, rather to be portable and power efficient. Everything about a laptop is a trade off. I suggest desktop for gaming and ultra book or mac air for a laptop.

The only reason someone should buy a gaming laptop is if they dont have a perminant place to store a computer, for example traveling due to work or living as a home stay.