Quantity   Component name
1 × ATtiny2313A microcontroller, PDIP Tayda: 0.99 USD each
1 × 0.1uF capacitor, ceramic Tayda: 0.01 USD each
6 × 1.0 Ohm resistor Tayda: 0.01 USD each
3 × 4.7 kOhm resistor Tayda: 0.01 USD each
3 × 2N3904 transistor Tayda: 0.02 USD each
3 × IRLB8721/IRF520 or other suitable N-channel MOSFET Tayda: 0.45 USD each
1 × 5x7 cm perfboard E-bay: 1.08 USD each
1 × Ikea STRALA light fixture (discontinued; sorry!) 5.00? USD
1 × 5V, >= 1000mA regulated wall-wart power supply ?
1 × Panel-mounted 2.1 mm power jack Tayda: 0.24 USD each
1 × Rotary encoder module with integrated pushbutton E-bay: 0.74 USD each
1 × 85x58x33 mm enclosure with clear lid E-bay: 1.66 USD each
1 × 2x3 pin header Tayda: 0.28 USD each
1 × 1x2 wafer connector 2.54mm Tayda: 0.02 USD each
1 × Housing connector 2.54mm 2 pins Tayda: 0.02 USD each
1 × Housing connector 2.54mm 5 pins Tayda: 0.05 USD each
7 × Crimp terminal connector 2.54mm Tayda: 0.03 USD each
1 × 3W RGB LED E-bay: 0.96 USD each
1 × 6-12 feet of 4-conductor wire ?
1 × Metal clothes hanger ?
1 × 44 mm diameter control knob E-bay: 0.78 USD each