I think it worth it. We are headed towards more organic programs but not fully so we still need a license as well.
What SLS stated about Tennessee is not the same case in Texas.
You just have to study the material (first year) and passed the test. You have within a year to take the test after getting the materials. The years after you have to obtain continuous credits from classes you obtain your license each year. The classes I believe will keep you inform about new products and new studies about the industry.
The price of the pesticide license is $150, but you will either have to get a Structural Pest Control license ($150) or a Nursery/Floral Certificate ($60). Then before you can even get your license after passing the test you must show proof of liability insurance that covers pesticide applications. This is where it will hit you pocket.
It is worth it in the long run. When you get larger you can have a separate division for spraying if you wish which can make you good money.