A good Nvidia card is essential to play PC games with high frame rates and at 4k maxed high resolutions on big TVs.  Dont forget that you will need atleast a quad core CPU and 16gb RAM for best performances.  Nvidia GPUs support CUDA for various applications.

The most important to look for in video card before buying is number of cores, SLI support for multiple GPUs, memory, HDMI output for cloning displays and maximum resolution it can support. Some video cards are power hungry, so watch out for the power consumption supply. If you plan to use for gaming, be sure you have a gaming cabinet with minimum 3 exhaust fans for venting heat, as otherwise excess heat will cause the video card to shut down. You can squeeze out the performance of video card by overclocking. Note that playing games on 55 inch or 65 inch 4k TVs, will put lot of pressure on video card causing it to overheat, therefore it is worth spending money on a high end card on the long run. You can compare the prices, and performance in nvidia website: http://www.geforce.com/hardware/compare-buy-gpus

I would spend from $125 to $500 on a cheap high end graphics card. I would recommend these cheap budget friendly video cards for PC games.

1. GeForce GTX 750Ti

Amazon: http://amzn.to/2cO7zq5

• Best entry level gaming card.
• Memory Detail: 2048MB gddr5bus Type: PCI-E 3.0
• PCI Express 3.0
• Memory Bit Width: 128 Bit
• EVGA GTX 750 Ti cards give you the gaming horsepower to take on today’s most demanding titles in full 1080p HD.
• EVGA’s 24/7 Technical Support
• Base Clock: 1176 MHz / Boost Clock: 1255 MHz
• Memory Clock: 5400 MHz Effective
• CUDA Cores: 640
• Memory Detail: 2048MB GDDR5
• Memory Bit Width 128 Bit / Memory Speed: 0.4ns / Memory Bandwidth: 86.4 GB/s
• Recommended PSU: 400W or greater power supply

 

Screen Resolution	4096 x 2160 pixels
Max Screen Resolution	2560 x 1600
Processor	1176 MHz
RAM	2 GB
Memory Speed	5400 MHz
Graphics Coprocessor	GeForce GTX 750Ti
Chipset Brand	Nvidia
Graphics Card Ram Size	2048 MB

Check prices at Amazon

2. GeForce GT 730

Amazon: http://amzn.to/2cObd32

3. EVGA GeForce 8400 GS 

Amazon: http://amzn.to/2cFCdWv

• Base Clock: 520 MHz
• Memory Clock: 1200 MHz Effective
• CUDA Cores: 8
• Memory Detail: 1024MB DDR3
• Memory Bit Width 64 Bit / Memory Bandwidth: 9.6 GB/s
• Recommended PSU: 300W or greater power supply
• Watch blu-ray and HD DVD movies.

Screen Resolution	1920 x 1200 pixels
Processor	520 MHz
Memory Speed	520 MHz
Graphics Coprocessor	Geforce 8400 Gs
Chipset Brand	Nvidia
Graphics Card Ram Size	1 GB

4. Geforce GTX 970

Amazon: http://amzn.to/2clXpj5

• Base Clock: 1165 MHz / Boost Clock: 1317 MHz
• Memory Clock: 7010 MHz Effective;
• CUDA Cores: 1664;
• Memory Detail: 4096MB GDDR5
• Memory Bit Width 256 Bit / Memory Speed: 0.28ns / Memory Bandwidth: 224.3 GB/s
• Recommended PSU: 500W or greater power supply

Screen Resolution 4096 x 2160 pixels Max Screen Resolution 4096×2160 Processor 1165 MHz Memory Speed 7010 MHz Graphics Coprocessor NVIDIA Chipset Brand NVIDIA Graphics Card Ram Size 4 GB

5. GeForce GT 610

Amazon: http://amzn.to/2cEoRXr

• Entry level cheap video card 
• DVI HDMI VGA
• PCI-E 2.0 16x
• Memory Bit Width: 64 Bit
• EVGA GT 610 delivers you a superior multimedia experience – every time.
• EVGA’s 24/7 Technical Support
• Base Clock: 810 MHz
• Memory Clock: 1000 MHz Effective

• Base Clock: 1190 MHz / Boost Clock: 1393 MHz
• Memory Clock: 6610 MHz Effective
• CUDA Cores: 768
• Memory Detail: 2048MB GDDR5
• Memory Bit Width 128 Bit / Memory Speed: 0.30ns / Memory Bandwidth: 105.76 GB/s
• Recommended PSU: 350W or greater power supply

Max Screen Resolution	4096×2160
Memory Speed	6610 MHz
Graphics Coprocessor	NVIDIA
Chipset Brand	nvidia
Graphics Card Ram Size	2

8. GeForce 8400 GS

Amazon: http://amzn.to/2dghvLJ

• Cheapest card in the market
• Base Clock: 520 MHz
• Memory Clock: 1200 MHz Effective
• CUDA Cores: 8
• Memory Detail: 1024MB DDR3
• Memory Bit Width 64 Bit / Memory Bandwidth: 9.6 GB/s
• Recommended PSU: 300W or greater power supply

Screen Resolution	1920 x 1200 pixels
Processor	520 MHz
Memory Speed	520 MHz
Graphics Coprocessor	Geforce 8400 Gs
Chipset Brand	Nvidia
Graphics Card Ram Size	1 GB

9. ZOTAC GeForce GTX 750Ti

Amazon: http://amzn.to/2dgimvH

• Video Memory: 2GB GDDR5
• Max Resolution: 2560 x 1600, Support 3x Display Monitors
• PCI Express 3.0
• Connectors: 1 x DL-DVI. 1 x HDMI. 1 x DisplayPort. VGA (with included adapter). Triple simultaneous display capable. HDCP compliant.
• Power requirements: 400-watt power supply recommended. 60-watt max power consumption
• CUDA and OpenGL support
• Full HD 1080p and Quad Full HD (4K)

Screen Resolution	2560 x 1600 pixels
Max Screen Resolution	2560 x 1600
Processor	1033 MHz
RAM	2 GB
Memory Speed	5400 MHz
Graphics Coprocessor	NVIDIA
Chipset Brand	NVIDIA
Graphics Card Ram Size	2

10. PNY NVIDIA Quadro K1200

Amazon: http://amzn.to/2cFOhqR

• Ideal choice for demanding CAD, 3D Design, and Media & Entertainment companies
• Compatibility with system enclosures ranging from compact SFF desktops to traditional desk side ATX towers
• Up to 2x the graphics performance of competing products
• Large 4GB GDDR5 GPU memory capacity
• Supports AutoCAD and SOLIDWORKS advanced photorealistic rendering
• Superior CAD graphics performance for value line business PCs
• Support for four monitors including 4K displays for signage applications
• Highest Highest performance low-profile professional graphics board
• 3D application performance and the ability to simultaneously drive four 4K displays

11. GeForce GTX 970 4GB

Amazon: http://amzn.to/2ddAOT7

 

• Virtual Reality Ready
• DirectX12 Ready / Gamestream to NVIDIA SHIELD
• Virtual Reality Ready / DirectX12 Ready, 3x DisplayPort 1.2, HDMI 2.0 and DVI-I
• Gamestream to NVIDIA SHIELD, 26% Cooler, 36% More GPU Power
• Base Clock: 1190 MHz / Boost Clock: 1342 MHz
• Memory Clock: 7010 MHz Effective; CUDA Cores: 1664; Memory Detail: 4096MB GDDR5
• Recommended PSU: 500W or greater power supply, PCI Express 3.0 x16
• Memory Bit Width 256 Bit / Memory Speed: 0.28ns / Memory Bandwidth: 224.3 GB/s

Screen Resolution	4096 x 2160 pixels
Max Screen Resolution	4096×2160
Processor	1190 MHz
RAM	4096 MB
Memory Speed	7010 MHz
Graphics Coprocessor	NVIDIA
Chipset Brand	NVIDIA
Graphics Card Ram Size	4 GB