Yeah not cheap matey...
Another good reason not to go too low is exhaust clearance. The OHC cars systems are rather low slung, especially where the downpipes come down to meet the rest of the system....even at std height, my 2300 Viva's system still hits some speed bumps if i have 2 people in the car.
Thats where Steve's stainless system comes in...it gives soooo much extra clearance, in fact it runs above the gearbox crossmember. but thats another major fork out of beer vouchers!! It'll last 20 years though i reckon.
Paul