Thats simple. I never made a claim so lets hear your explanation. To do a single turbo on average you need a bigger turbo. That bigger turbo probably wont be found in junk yards so you will be paying a pretty decent price for it on average. So u have more invested in the turbos for a single than a twin from the start. Then you need a wastegate where as with twins if u run t3's you already have internal wastegates. Twins ahead again. Then you dont have to worry about a cross over pipe for a single. Dual in/single out IC's are getting cheaper everyweek as more people are starting to make them so that will make the cold side of a twin just about as simple as a single. People say you have twice the oil feeds and drains which is true.
The point is the which one is more expensive is PURELY up to the owner. If you weld your turbo kit then it doesnt matter which way i go, your twin or single setup will ALWAYS be cheaper than my setup since i cant do the labor myself. The labor for the hot side of twins is cheaper...atleast in my experience. The turbos are cheaper. The IC is a tad more expensive but then i dont have to worry about wastegates.
But then if you go all out with twins, then it will be more expensive. My claim is that either route can be done for about the same price. One of them can be less than the other depending on your situation...i.e. what you can do and who you know.
Now, whats your reasoning? I think i explained mine well enough.
by the newbie 
