Anyone can buy a part, just like anyone can purchase the products to build an airplane. However, can just anyone assemble the parts correctly to ensure the end user is safe? Why is it that so many people disregard the professional training that goes into becoming a top notch trades person. All they see is the price of the part. What about the cost of obtaining a trade certification, the continuing education, the liability insurance, fuel, vehicle maintenance, vehicle payments, insurances,...