The answer to 'how much does grout cost' is that the cost of grout can vary widely depending on several factors. Grout is typically priced by the square foot or by the bag, with prices ranging from around $0.50 to $5 per square foot or $10 to $50 per bag, on average.
The main factors that influence the cost of grout include the type of grout (sanded, unsanded, epoxy, etc.), the quality of the grout, the size and location of the project, and whether you're doing the work yourself or hiring a professional. DIY projects using basic grout tend to be on the lower end of the price range, while custom or specialty grouts installed by a professional can be more expensive.