I personally don't use percentage of construction when I provide cost on architectural services. However, before I am aware of all the project details, location, complexity and type of finishes, this is just an initial conversation placeholder. To provide an effective proposal, I need to know a lot more than what you've provided in this post and that's okay. @Danilo Grullon
You don't know what you don't know. I've had more folks than you think in your same position who look to cut cost with the wrong professionals and then regret it. When you're spending hundreds and hundreds of thousands of dollars on the construction of a project trying to cut $30k-$40k is arguably negligible. (Miami is an expensive market too.) You can save that amount or more simply by designing and specifying the right foundation, exterior facade assembly and/or roof system. Let a Drafter and Engineer design your house and you may face more problems than you think.
All the best on your project.