Marcellus Jacobs started out experimenting with the typical "Water Pumper" wind mill. He lived in the Dakotas and was famous for developing the "Jacobs" Wind Turbine. He established quite early, that there was no viable output in low wind areas.
In the real world, you MUST get the Turbine, AT LEAST 30 feet above ANY object within 300 feet of your machine.
I live on top of a nice hill, and, I still need at least a 90 foot tower to get in an UNinterrupted wind stream. Anything less, and the machine will be constantly yawing, looking for the steadyness in the turbulent wind pattern. I was in the Business for several years. A tower is $$$.
As far as the variable pitch blades, I made such a system, in 1979. It had a fixed blade angle of attack, and, as the winds and blade speed increased, the blades would twist to allow the tempering of the winds and governing of the generator. The 4KW machine I built, would start up in 7.5 MPH winds, but would not produce power until + or - 10 MPH winds. As is said here a lot, "it depends". It would run at 250 RPM's max, with a 15' dia. span.
I have started another variable pitch hub, to fly a 2.5 + or -, Wind machine. It's for possibly selling the system to a neighbor. I have Solar Cells for 3 panels, and a small stream for Hydro. ALL 3 systems will be minimal output, and houses and neighbors are not even a player where I am.
Except for my wood shop, we are VERY frugal, and might be nearly off grid, But, I probably won't be able to keep a big battery bank up to snuff, even with all 3 systems. It ain't so easy, and, i DO have enough experience from those 7 years, living in the country, in Arkansas.
In my humble opinion, that $6500.00 would be better used to start a fund to develop an Organic Rankine Cycle Refrigeration-Generation System. There are several people, on other forums, coming close to having a working system. That's what I'm studying, right now, along with Electric Drives, for my, one day, 3 Wheel Moto-car type vehicle.