The Stillen ones aren't that badly priced, To make these, a couple of K&N filters $160, couple of turbosmart 45's $60, couple of turbosmart 70-76 reducers $60, couple of turbosmart 76mm joiners $50, turbosmart clamps $70, couple of 76mm S/S 90dg bends $70, S/S tube & F/B $30. There's $500 just in parts without paint!
Then machine a couple of MAF adaptors, tig gas & wire plus labour nearly 8-9hrs.
So at my labour rate your looking at close to $1000!! Scary a!
I just do it because I enjoy making stuff.
So yeah, the Stillen ones aren't that bad after all