Among the various experiments, and understanding the requirements set by Farhan I can suggest these two options: 1) 0.96 - 1.3 inch IIC Serial OLED Display 128X64 I2C SSD1306 2) Nokia 5110 84x84 pixel display.
3) ILI9341 display driven by additional arduino nano. The first two have wholesale prices of a couple of dollars, and are simple to use and program. Obviously if you need something better (colors etc ...) you need other displays but the problem is the inability to exploit it fully with the arduino 328p. Possibly you could build an "intelligent display" using a 2.2-inch SPI display and 65000 colors ILI9341 driven by an arduino that exposes via liea I2C serial commands "similar to the nexion" towards the main arduino on which the Raduino code runs. This way I think the costs could go: $ 4 on the display and about $ 2 for a dwarf arduino.
Best 73 de Giuseppe, IK8YFW
