Antony, you won't have any problems selling it. Some bloke sold it to me (forgotten name), and i sold it on to you! I was going to use it for my CG13 conversion, and being a big name manufacturer, and a quality built part, it's definitly worth what you paid. To get that in the UK, your looking at a 6 week wait or more, it's rare and i don't think people understand that! If your doing a turbo conversion, it's worth paying the price for decent bits. That HKS manifold is worth that price!
Anyway, with regards to making manifolds & decat's and selling them on the MSC, your probably going to need to discuss Trade membership with Kev.