Saving money is important, whether you're just getting started or getting more chickens, so building a chicken coop yourself is a great solution. Good ready built coops are expensive - and you will still have to assemble the pieces themselves, so find some well-produced plans and get going.
Building a chicken coop is an ideal family project. Children can follow the instructions and tell you what to do next, they can assemble sections and may be able to build the whole coop themselves.
At the outset it is the size of the flock that determines the type of coop. If you have, or plan to have, about three hens, then a chicken ark would be a good choice.
Chicken arks can be moved each day so the chickens get fresh ground to graze, or you can leave them in one place and let the chickens out. A chicken ark is a simple triangular shape with a nest box and roosting space at one end and a run at the other. Building a chicken ark is a simple project that would take a day to build.
It will take you most of a weekend to build a larger hen house with a run, but i's still a simple task if the design is based on simple shapes. This is a good design for around five hens. if you choose to build an ark as well, you then have something to move the hens around as well as a chicken coop with a fixed run.
You could build a chicken ark as well, so you have a moveable as well as a fixed hen house.
There are good plans that include all three designs which are the obvious choice if you really want to save.