Software & Electronics Expertise
Building your own racing drone requires expertise across the a variety of technology disciplines like soldering, knowledge of electricity, reading digital multi-meters, RC model building, etc. While much of the best software is open source and free, it takes some understanding to apply the patches. Patching some components requires building custom cables. There is much to learn if you don't come from an RC modeling background.
I include configuration separate from software since configuration deserves it's own section. In fact, it's a bit of an art form. A successful build is useless without proper configuration. The type of configuration you need depends upon the components and brand of components you use. Most flight controllers require some configuration for smooth flight. For example, typical small racing drone design places camera on the top at the front of the aircraft and battery on the rear. This means it takes slightly more force for the flight controller and motors to make corrections to the front and back of the aircraft than it does side to side. These differences must be accounted in configuration. Since there is no standard build there is no standard configuration. My settings are specific for my aircraft. Another example, Electronic Speed Controllers(ESC) are driven by the flight controller and often require software different software since may of these ESC's are intended for model aircraft. Flying multi-rotor is a far more demanding environment than fixed wing since multi-rotor aircraft have no control surfaces and thrust vectors are controlled entirely by differences in motor RPM. Most of us do not run the stock manufactures ESC code but instead apply custom open source software like SimonK or BLHeli. Flight and FPV cameras also require configuration for optimum performance.
Experience is a painful teacher. I learned early on through trial and error the type of acceptable construction and configuration short through needless crashes that could have been avoided. I have had shorts in carbon fiber bodies that resulted in frame warping. I have had screws that were checked before flight unfasten themselves in flight. Building a reliable aircraft can be done but it takes some education. My very limited experience provides me genuine appreciation for Boeing's safety record. I don't know, but I can imagine, the additional challenges flying aircraft reliably at 45,000ft or more.
There is no standard with expenses and it's changing all the time. When I first started there was nobody in my area building racing drones. At least, any that I know personally. It cost me a lot more money than it should since I made a number of mistakes.
The facts, flying radio controlled models has been around for 50 years. Not a single individual has been killed by a hobbyists drone. No hobbyists aircraft has ever been used to deliver an explosive payload or even in the commission of a crime (so far as I know). It's difficult to understand the origin of disproportional concern from governments around drones. Perhaps the fear is historical, the term "drone" has been used mostly to describe UAV aircraft governments use for surgical strikes over the past 20 years. Along the way the term was unwittingly co-opted to multi-rotor and hobby aircraft equipped with FPV gear. Now the hobby community is surprised and frustrated fighting an uphill battle to improve sentiment. Government concern around drones may discourage public interests but it definitely slows commercial developments like Amazon.
Most of the racing drones frames are made from carbon fiber. Even so, a crash from a significant altitude and speed does significant damage to an aircraft. The problem with learning to fly is that the ground is hard. A challenge to any Ready To Fly(RTF) platform is to develop easy to replace plug and play components, limit ground time, and UPS delivery wait times.
Everyone's RTF Different
To the consumer RTF means everything you need to put an aircraft up in the sky and have some fun. Potentially this is a lot of gear like: aircraft(frame, motors, flight controller, ESC's, flight camera, FPV camera, receiver, video trx, OSD, SD Cards, wire and misc, etc), transmitter, LiPO batteries, battery charger, FPV goggles or TFT, antennas, and more. Making the consumer successful at flight requires simple integration, reduced configuration, packaging options, and low-cost effective replacement options. Flying racing drones is not like flying camera platforms. There's going to be some crashes. Retailers should work with manufactures and look at this as an opportunity to build an ongoing relationship with the public.
Bringing success to the public is one of the hallmarks of DJI and the Phantom platform. The Phantom is larger camera platform and not a racing drone but making flight simple and customers successful has increased public interest and also interest that spills over into racing drones. Commoditizing the electronics for racing drones, reducing configuration complexity, improved RTF component packages, easy access to individual low-cost replacement parts, will go a long way to put racing drone technology into the hands of public would be fliers. I will continue to fly my research projects and enjoy them but the addition of simple RTF options are a welcome improvement.