Acrylic is a way of displaying prints in a very sleek and modern way. The print is made on a high-gloss, very smooth paper which is then adhered to a lightweight but stiff backing, usually dibond.
Then a sheet of 6mm thick acrylic is mounted to the front of the print using an optically clear adhesive layer. The result is a crystal-clear, high definition print with no border that looks as though it's floating on the wall.
Because the process is very finicky, any dust or defect during the process means the materials can not be reused, so it's very expensive to produce - hence the higher price tag. However, it is definitely a striking way to display a print!