Considering the aesthetic upper hand that natural stone steps have over ordinary boxy concrete stairs, there must be a reason that all exterior stairways are not made from stone. Cost is the most obvious reason, and stone will never win a battle of frugality with a set of precast concrete stairs. For more involved projects, however, the winner isn't always so easy to predict.
Concrete steps have some installation advantages over stone steps. Concrete steps can be relatively easily cast in place at the same time a project's concrete walks or patios are being poured, saving time and labor costs. Precast concrete stair units can be simply dropped into place. However, stone steps often require preparation of the subsurface, the application of mortar between the stones and possibly the cutting of individual stones to fit the design.
Cast concrete can be embellished using liners inside the wooden forms that produce rounded edges on the steps, and custom-built forms make curved contours and varying shapes easy to achieve. Stone step designs are limited by the size and shape of the paving stones used, but the natural contours and colors of stone make possible rustic and traditional designs that are difficult or impossible to reproduce in concrete.
Natural stone has an aesthetic appeal all its own, and typical unadorned concrete has a difficult time competing. Techniques that augment the appearance of cast concrete, though, make it more attractive than merely undecorated gray blocks. Pigments mixed into the concrete during casting make available a virtually limitless palette of colors, and concrete steps can be made to harmonize with their surroundings or make a bold statement of their own. Patterned stamps pressed into the concrete before it dries mimic other materials such as brick, flagstone or tile.
As a material, natural stone is significantly more expensive than concrete, and in many situations, stone steps will cost substantially more than concrete steps. The greatest price differential is between precast concrete stair units and custom stone designs. However, when the design of a concrete project is complex or requires many steps, the labor costs associated with cast concrete quickly close the gap between it and stone. When the durability and longevity of stone are factored in, stone may be a cost-effective option for complicated projects.