A license (c6) is needed to advertise and spray for weed control which includes when it is included in a maintenance contract.
To check if someone and a company is properly licensed to advertise and spray for weed control ask them what their license number is and contract the Nevada Department of Agriculture.
The cost of spraying will take into account how long it will take to do the work, what prep work needs to be done, and how much and what type of herbicide is used. Sometimes more than one application is needed.
There are some granular herbicides but they need to be activated by water and considering when and how much water we get can affect if and when it gets activated. If can get blown out of the landscaping into areas it is not intended for and or activated when it is not needed which is pollution and wasteful spending. Granular fertilizer has a time and place for when it is / should be used and we assess each property on a case by case basis.