Nvidia - price, buy/purchase in the online store KSMtop
Amazon.com: NVIDIA Quadro 4000 for Mac by PNY 2GB GDDR5 PCI Express Gen 2 x16 DVI-I DL, DisplayPort and Stereo OpenGL, DirectX (Boot Camp), CUDA and OpenCL Profesional Graphics Board, VCQ4000MAC-PB :
QUADRO M2000-LENOVO - Refurbished - LENOVO NVIDIA QUADRO M2000 MAXWELL GPU 4GB 768 CUDA CORES MEMORY INTERFACE 128 BIT GDDR5 MEMORY BANDWIDTH 106GB/S PCI-E 3.0 X16 ( 4 ) FOUR DISPLAYPORTS GRAPHICS PROCESSING UNIT VIDEO CARD
NVIDIA Quadro 2000 by PNY 1GB GDDR5 PCI Express Gen 2 x16 DVI-I DL and Dual DisplayPort OpenGL, Direct X, CUDA and OpenCL Profesional Graphics Board, VCQ2000-PB