What you are paying for
A sign board’s price is made of four things: material, fabrication, lighting and installation. Two boards of the same size can differ several times over in price depending on how those four are chosen.
Size
Flat boards are priced by area. Letters are priced by height and by how many there are, because each letter is made separately. A long name in small letters can cost more than a short name in large ones.
Material
From least to most expensive, as a rule: flex or vinyl on a frame, ACP board with vinyl or cut letters, acrylic or aluminium profile letters, stainless steel letters. Finish matters too: gold, copper and mirror finishes cost more than matt.
Lighting
A lit sign needs LED modules, a power supply, wiring and a way to open it for service. Front-lit letters need a module behind every part of the face; back-lit letters need them behind the body. More even light means more modules.
Fixing
Height and access change the installation cost. A board at shop-front height is fixed from a ladder. One on the third floor needs scaffolding or a lift, and often a steel frame.
What to send for an accurate quote
A photo of the wall taken from the road, a rough width, whether it must be lit, and your name or logo as you have it.