You may get a better chance of an answer if you put up a picture of the style you are considering.
Even then there is a massive variation between suppliers, In the past I have made items with a good profit margin for £300 and told by the customer they had been quoted £500 for the same work.
Then there is hand forged or bought in weld together components, another variable that will make a world of difference to the price.
The chap in the unit next to mine used to charge £100 per metre for plain balustrade with 12mm square bars for the infill. Any scrolls, twists, posts, finishing etc were extra. That was around 4 years ago.