How much do you usually set aside for design work?

I recently hired a designer to help me with branding and packaging for my small side hustle, and um, I have to say, the costs caught me off guard a bit. I mean, the results were great and all, but it felt like every little tweak or revision added up fast. Wondering if this is just how it goes or if maybe I didn't plan well enough from the start. Curious how others handle this stuff—is it normal to underestimate these costs?