nVidia Quadro 4000 2GB GDDR5 PCI-E x16 HP 608533-004 707253-001 [Quadro 4000] - $199.00 : Professional Multi Monitor Workstations, Graphics Card Experts
Refurbished: nVidia Quadro 4000 2GB GDDR5 PCI-E x16 2.0 Graphics Video Card With DVI and DisplayPort Outputs 38XNM Standard Height Workstation Video Card - Newegg.com
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 :
Amazon.com: HP 671137-001 NVIDIA Quadro 4000 PCIe 2.0 x16 graphics card - With 2GB GDDR5 SDRAM memory : Electronics