I need one 4×8 sign to be attached to a wall. I don’t want any fancy graphics, just black print on white background so what is the cheapest option? Can I attach the sign with screws?

We can cut out black (or any other colours) vinyl characters and apply the image to 96″x48″x4mm (or 8mm) white coroplast sheet. This option is less expensive than digital print: one 4’x8’x4mm coroplast sign with one colour cut out vinyl graphics on 1 side is $100.00; 10mm white coroplast sign is $140.00.
Coroplast is rather soft material so you can easily attach the sign to a wall with screws, just use washers not to let wind blow out the sign.