Inspectors know what to look for and have seen a range of situations. They investigate areas of the house and its components that the average homebuyer would not think about. Education, training, and experience are important. Ask the inspector if they belong to a home inspection organization. Qualified home inspectors must past tests and meet minimum qualifications to be accepted for membership.
Home inspections are a good value.
The cost depends on how far the inspector has to travel, how big the house is, the type of house, its age, the location of the property, how many other inspectors are competing for the job, and many other factors. Call several inspectors for their qualifications and get an estimate on the price. If you are located in a small town without any inspectors, you might, as an alternative, be able to hire a local city or county building code inspector on an after hours or weekend basis. Paying for the inspection is your expense. Your lender can explain further about the cash requirements necessary but basically it is the down payment requirement.