Is $1,400 to refinish 630 sq ft of wood floors (no stain) a fair price?

I have two floors, 415 sq ft and 215 sq ft, that I'm looking to refinish without stain. I've received quotes ranging from $1400 to $6000. The $6000 company claims they use better material and put more care into their work. I'm unsure about flooring quality and concerns. I have a 3-year-old, 60lb dog, which has caused a worn area by the back door. I'm considering whether to choose a cheaper option now and revisit a more expensive one later. I plan to ask follow-up questions about the type of poly (water or oil-based), the number of coats, and prep work to protect other areas like HVAC.