Bible commentaries are a world unto themselves - it very much depends on the particular interpretative position held by the author and how much you are prepared to pay. The effect is that you can end up buying anything that will support your own beliefs - which renders the whole exercise pointless.
For what it is worth I reference the New Interpreters Bible - a multi volume library which is pretty expensive to buy as a boxed set. However, you can but a volume at a time and progressively add to your selection as you interest expands. This set is a middle of the road series which means it is neither liberal nor fundamental in its outlook. There are any number of contributors who author those section in which they have expertise. The overall effect is that you get a pretty good bang for the buck.
But please do your research - and for that the web is a very good tool. See what others have to say about particular productions. And, remember, a good commentary will last you a lifetime so it is worth investing wisely.