Need advice on building a logistics app

I’m planning to get a logistics app developed for my startup here in Dallas. The main goal is to handle delivery tracking, route optimization, and real-time driver updates. I’ve been looking into local app developers, but the more I research, the more I realize how different the quotes and approaches can be.

Has anyone here actually worked with any Dallas-based development team for something similar? I’m trying to understand what’s realistic in terms of cost, timeline, and communication. One of my biggest concerns is getting stuck mid-project with unexpected add-on costs or unclear updates, I’ve heard this happens often when requirements change a bit along the way.

Would really appreciate hearing about your experiences