Everything is relative, so it is hard to answer. Slides are meant to be slippery and in a normal installation are 6 or 8 feet above a cement patio so we do not install a lot of “standard” slides. The slides we are requested to build are mostly the built-in type and those can be considered a costly feature, due to the labor and materials required to build them. The slide is a feature like any other and may be added or deleted as the design process evolves. It can and should be priced out separately so that it can be included into the budget, or not, if it does not bring enough value for the cost.