You easily salvaged NPN Transistor KF13003A from faulty flourescent light bulb for free. Transistor are not cheap and it and sometimes it's not easy to find but in household product like the flourescent light bulb you can get one. There are also film capacitors, some diodes, resistors, and inductor you can get for free.
●High Voltage Capability
●High Speed Switching
●Low Spread Of Dynamic Parameters
●Minimum Lot-TO-Lot Spread For Reliable Operation
●Electronic Ballasts For Fluorescent Lighting
●Switch Mode Power Supplies