Surveyors normally work on an hourly rate basis – professional fees vary. A detailed examination of a property may cost a lot of money, particularly if the surveyor becomes uneasy about something and needs to back with a builder to have some part opened for inspection. Checking services (for example a septic tank and percolation area – see paragraph 8) would be prudent but takes time and will therefore increase the cost of a survey. The reason it costs so much is because such checking is time-consuming and because most things to be checked are either inaccessible or not readily accessible. For this reason, drainage is usually not checked other than in a simplistic way.
By and large you get what you pay for.