Septic fields, am I being ripped off?

I don't know where you are in Canada related to this location but you may want to read through this. Type 2 is going to cost you every year for them to come out so they are building in job security.

http://www.crd.bc.ca/wastewater/septic/onsite.htm

What is a Type 1, Type 2 or Type 3 septic system?

In 2005, when the provincial government changed the regulations governing septic systems, it defined them into categories of Type 1, 2 and 3.
Type 1 is treatment by septic tank only whereby the sewage is held in the tank before heading into a drainfield. It may be gravity fed or pumped into the drainfield. Type 2 and Type 3 systems introduce further treatment in order to produce a higher quality effluent that can be discharged into a smaller drainfield.
Type 2 and Type 3 systems are often used where there are site or soil constraints that prevent a Type 1 from being used. These systems are often referred to as package treatment plants and they have mechanical and electrical parts that require more frequent maintenance.