The cost of choosing a qualified Saint Marys interior decorator differs a lot. The majority charge per hour, with the current market amounting to $50 and $200 per hour. You would probably pay this along with the cost of home furnishings, accents, artwork, etc. A few interior decorators in Saint Marys charge their customers by "marking up" the decor they choose. For instance, chances are you'll say yes to pay a 15 percent markup fee to your interior decorator concerning all items purchased.