What is the cost for an architect or structural engineer in LA

[Marcos Urvina]

Hello all, My name is Marcos Urvina, i live in Los Angeles Ca south bay area. I want to take advantage of the new rules and regulations passed to make it easier for homeowners to build an Adu in there house lot. I plan on building a 300 sq ft studio in my backyard and either rent it out long term or maybe do Airbnb. What would be a fair and reasonable cost for an architect or structural engineer to design and submit plans on this type of project? Do they charge by per sq ft, hourly? Any advice, input, or experiences would be appreciated thanks.