Have you gotten just one price so far? Stainless Steel raw materials cost including welding supplies has skyrocketed over the last three years but 300 bones a foot sounds a bit pricey. The project as you described it will be a highlight of your home and I am sure the guys priced it to make it a beautiful thing. Well anyway just a thought, you might want to get some others to price it, but to make a handrailing that has asthetic appeal takes some real world skills. I cannot think of any metal materials that will have the look and or longevity of SS. Have you checked on some of the newer polymered plastic products?

Make sure you will pass code with cable railings.
They are NOT acceptable in many places.