It is difficult to provide a definitive answer as to what a reasonable percentage of the cost of a home to pay someone who offers to create a website and promote the sale of the home would be. The appropriate percentage would likely depend on a number of factors, including the size and value of the home, the level of competition in the local real estate market, and the specific services being offered by the individual. In general, it is advisable for homeowners to carefully consider the costs and potential benefits of using such services before entering into any agreements. It may be helpful to seek advice from a real estate professional or other knowledgeable source before making a decision.