Strong, recognisable and remarkable brand can be one of the most valuable asset of your company. The way how you are perceived by the customers, can significantly affect your business.
By investing money on high quality marketing materials, you can:
sell more (your products looks better than competitive),
reduce marketing costs (once spent money will be returned multiple times - materials can be used many times, for different purposes),
build trust (showing your company you seem to be more open and professional).