The model you have chosen is a low budget printer. You cannot expect much from this. Features like endstop of extruder, up-gradation, heated bed will be unavailable.
The supported extruder is single in this printer. Therefore, you need to buy another printerboard Extruder, stepper motor, hotend and more wires. These will cost another $100. But you will be unable to work with these easily. You can adopt another way that is you can upgrade to RAMPS. The cost will be almost same and this will leave option for further upgradation. But this options will impose a limitation so that the bed space will be narrow down. The maintenance will also be lot more difficult.
Therefore, my suggestion is that, increase the budget and buy a convenient one.