I dont know how much they are...but there are a bunch of decently happy ON3 performance turbo guys on the corral forums.
But i think they can give say a KB kit a run for which is most expensive. For the options available today it is hard to simply say a turbocharger set up is more expensive. There are wayyyy too many variables involved. Sure...you can find a used
Vortech setup for dirt cheap. But then there are KB chargers that cost a lot new. So...what is the comparison based off of?
Both need fuel upgrades. Both "should" get ignition upgrades. No gain or savings there.
Many will attack the quality of ON3, but there are happy customers. I see the "young guy" mentality here...especially a claim of 18psi on a stock motor....i hope he realizes thats a grenade waiting to blow. But in reality, this young guy just doesnt realize the type of board he posted to. Kurt for instance, has said on multiple occasions how horribly expensive turbo setups are. Is he wrong? No. But there are more options than just that set up our there that dont cost that much.
If he made this thread in the turbo section on the corral....it would be a different result.
Twins will blow a stock block if ran at "max".
A single will blow it.
A supercharger will blow it.
So...pick your poison.
And....keep researching. If you dont get the response u want...keep researching. Some of the "special" guys around here wouldnt be special if they did what the general public said was the "right" thing to do.