These Method wheels and the Sparco's are not competition wheels like the Team Dynamics Pro Rally wheels are. The Method wheels and the Sparco wheels are cheaper because they are manufactured the cheapest way, gravity cast, and they are made in China. Method doesn't manufacture wheels, nor does Sparco. These are brands in name only.
All Team Dynamics wheels are manufactured in the UK, by the same factory, Rimstock Plc, the largest OEM wheel manufacturer in the UK. There is no secret to this. All you need to do is visit Team Dynamics website,
http://www.team-dynamics.com . As the Pro Rally is actually used on a professional level, and is the same, unmodified wheel you can buy, it is not in the same, lower class as either Method or Sparco. Not even close. No WRC team is going to slap on a set of gravity cast wheels made in China and hope they don't break and crash out. Just because a wheel "looks" like a rally wheel, certainly does not make one.
Many companies operate this way. It is more the norm than not. Contract with Chinese/Far East wheel manufacturer and go from there. Many of the brands Tire Rack sells are their own private label wheels. Bremmer Kraft, Sport Edition, Sport Tuning, and TR Motorsport comes to mind.
As far as beating prices go, you can buy the real thing or the cheap copy. Cheap, fake Rolex or real Rolex. Fake competition wheels, real competition wheels.