First and foremost, you are investing in a workflow or a process for studying the Bible.  I strongly encourage you to test drive the software prior to making a decision.  Are you comfortable with the search process?  Are you willing to get more training on the advanced features and syntax?  Have you asked other users about the weaknesses in the software?  How will this software specifically enhance your study of the Bible?  Choosing software with the wrong workflow is like driving a Ferrari on the M2 during peak hour… you will get there – slowly.  Now let’s talk about some of your options:

Both the ESV Study Bible website and Biblegateway.com provide a simple searching interface and basic textual and commentary helps.  E-Sword is a robust tool for studying the Bible.  You owe it to yourself to download E-Sword to see if it suits your needs (and it’s free).

Bibleworks is the tool of choice for the ninja exegete.  The software specialises in the close study of the text with excellent lexical tools.  You need to be comfortable with the original languages to use this product.  There is a significant learning curve for the advanced syntax (is there any other way to become a ninja)?

Logos is more accessible for people without experience in the original languages and for accessing the wealth of theological resources in Christendom.  You should consider the Silver Scholar package or the Platinum package.  Without the NAC, the cheaper packages don’t have enough real-use value.  The Platinum package adds the NIGTC, the PNTC, and the excellent BECNT.  If you are considering Logos, also save some shekels for the MacArthur commentaries, the pricey NICOT/NICNT set, and the theological journals.

We’ve only had these tools for the past 15-20 years of human history.  Most of our favourite authors could only dream of having access to our wealth of resources.  If you’re going to buy it – use it!