Some GPS units sell for not much more than $50. Most are fairly easy to
enter coordinates. As you pay more money, you will receive built in maps.
The more money, the greater the detail. Some of the more expensive ones
allow you to download detailed city or topo maps for a particular area.

Most of the people who buy gps units either love them or get frustrated and
abandon them. In either case, you will often find them selling them. The
people who use them frequently will upgrade, while the disappointed ones
will abandon them.

One caution about purchasing a used one from a friend. They might have
purchased them for $300 and assume they are giving you a good deal for $150,
when in fact a new unit for under $100 will have better maps.

I recently purchased a Magellan GPS with built in mapping program for $10 at
a swap meet. Newer ones use 2 penlight batteries. Older ones use 4. Try
to get one that uses 2.

Using any of the coordinate systems, you can learn to approximate distance
and direction in your head. It is a fun mental exercise. Be sure to set
the coordinate system and datum to the same as the person reporting.

Colin