A home inspector should have some form of professional training. They should belong to an association.
Most associations have minimum requirements before accepting a home inspector to their association.
Although, if he does not belong to an association it does not mean the home inspector is not qualified. You need to find out more about the home inspectors background. A professional home inspector reports all potential problems, which in most cases will save you the cost of the small inspection fee. Pricing is based on each home inspection company. There might be extra fees for additional services.