Basic GPS Systems
The basic units are just the plain old receiver with minimal set of features. A basic unit can be bought for around 100 dollars.
These simple devices have the basic functionality of reporting the location in terms of latitude and longitude. They may also have a base map (a very high level map that contains major highways and few Points of Interests) of a region. Basic units have limited processor and memory capacity.
These units are ideal for a person with low budget whom would like to use GPS for basic navigation, educational activities and fun.