spider 2

Here are the parts:

1x Arduino Pro Mini

1x DC-DC(12-5v/3A output)

1x HC-06 Bluetooth module(option)

12x SG90 servo(3DOF for 4 legs)

1x 3000mhA Li battery

1x 12V Jack

1x 680 Ohm 1/4 watt 5% Resistor

1x 3mm Blue LED

1x Tactile Switch

1x 5x7cm perfboard

Some male and female pin headers

Small guage wire(Solid or Stranded)

I believe that these parts are most popular and not expensive. They are just cost me about 2,000 Taiwan dollar.