Those are not very big, must be fancy for that price? How ornate are they? What are other design items, full frame, privacy screen, hot dipped galvanized? lock sets, Tube or solid, gold leaf finish?
Seems like for a basic solid gate maybe a few basic ornaments and perforated sheet metal screen would be around $1000 each. installed.
I bought raw materials from here: http://www.metalamore.com/ma/ and also a stick welder and made my own stair railings. You might want to look at their components and galley images anyway.