Great question! Ultimately, it comes down the materials used to produce each display. Cast Acrylic is one of the highest grade forms of plastic giving it a glass-like appearance and is considered a renewable material (you can polish out any scratches and imperfections caused by normal use). Cast Acrylic is also the most premium and durable form of acrylic allowing us to ensure a 250lb weight limit for each display. Our Buildable Acrylic Displays are designed out of a light weight extruded acrylic and requires a very simple assembly process which brings down manufacturing and shipping costs that we pass on to our community.