[Aussie Mike]

Of the few sets I've built with cats I don't think I've had any change out of $1K for materials on any of them.

I heard the fine for not having cats was substantial i.e. about $12,000. Where as if you are too noisy it's a mater of fix it and get it retested.

These modern cats are pretty free flowing and don't hurt performace too much so I'll do my small bit for the environment and hopefully have a better chance of talking my way out of an infingement notice.

Cheers