If you are looking for a cost-effective, single-volume commentary on the entirety of the psalter, then this is a decent choice. Craig Broyles basically provides a very basic interpretation of each Psalm. Of course, due to the length of this text, it lacks some of the depth and detail that is offered in larger, multi-volume commentaries on Psalms. I do not agree with Broyles on all of his interpretive choices, but this is, nonetheless, a good place to start. If you are looking for something more in depth, I would highly recommend the Word Biblical Commentary set by Craigie, Tate, and Allen - but this set will set you back about $100.