Antique (or antique-style) birdcages are often popular as collectors' items or as household decor but most are not suitable for housing live birds, being too small, or of unsafe materials or construction. Good quality cages designed for pet birds are more suitable.
Most parrot cages are made or wrought iron and painted with a non-toxic paint referred to as powder-coating. However, the newest trend in the market is cages made of solid stainless steel. Large parrot cages made of stainless steel can cost thousands of dollars and will actually outlive a powder-coated cage by 5 to 6 times. While small cages are relatively cheap, large parrot-sized cages can cost hundreds or even thousands of dollars. The materials used to build the cages has a lot to do with the price level.