Choosing packages can be a tricky decision on any platform. The "right" package for you might not be the right one for me. Normally my preference has always been to buy as big of a package as I could afford and reasonably think that I would use, because you usually get a better deal when purchasing up front. However, Accordance has a strong upgrade program which only charges you the difference between your previous package and the one you wish to upgrade to, meaning that you will not end up paying more for starting small. This policy alone makes Accordance a strong choice, even if you cannot or are not willing to make a large investment. Be sure to look at their How to Choose page for help making your initial purchase.
As with all such programs, the packages that you buy depend on what you want and need. While the initial purchase price for some of them may seem steep, these library items are yours forever, as long as you use the application, and do not need to be upgraded. In a sense, Accordance is like an e-book reader (although it is much more than that), and the library items are books on your shelf. Of course Accordance integrates these new library items with the rest of your research and study tools, making the whole program more powerful.
It is possible to sit down in front of Accordance and simply start using it. The main window offers a quick-search access to any verse in the Bible, and a dropdown menu offers you a range of books from which to choose. There's even a Dashboard widget which will look up a verse and quickly insert it into any application; but there is so much more to Accordance. Considering that this software is likely to represent a significant investment, I highly recommend the demo videos and video training sessions which are offered free of charge (some of them are based on version 7) or the weekly video podcast [iTunes link]. Some of the training videos are also available on DVD for $15US but all of them are available online for free. I watched a few of these videos before I even installed the software and within an hour I felt like an expert.
The time you spend watching the videos will help you understand how the program is designed and how the various tools work together. If you're not sure you're ready to take the plunge, a free trial is available to let you get your feet wet. Customer support was extremely responsive, and there are also user forums available, as well as a company blog which shows how actively the software has been developed and how often new versions are released.
About the only difficulty I had with the program is that resources are referred to through abbreviated names. When this involves versions of the Bible they are fairly straightforward, it's no big deal; for example, those who are familiar with translations of the Christian Bible might easily recognize "NASB" as the New American Standard Bible. Other abbreviations, however, such as GNT-T, GNT-TIS, HCSB, BBE, and LBLA might leave newcomers like myself confused. As you spend time with the program and the titles in your library, these abbreviations will become more familiar. The learning curve can be overcome, but don't be surprised when you find the initial ascent to be fairly steep. Also, it should be noted that any Bible study software will have a similar initial investment price and learning curve. If you still have questions, technical support is available through the forums, FAQs, and through phone or email. There are even free seminars held at select locations in the USA.
Choosing Bible study software for the Mac is now like choosing between a camera from Nikon or a Canon. Buying 'packages' for one software program is like buying camera lenses: they aren't interchangeable, which means that switching later on will be an expensive proposition. It makes sense to do your research beforehand and make sure you are buying the right one for you, rather than listen to someone else tell you which is "best" -- it really comes down to personal preference. Accordance has a long track record on the Mac, a solid reputation, and an extensive library of research tools. Combine that with an active and ongoing development cycle and extensive tutorials, and you've got a Mac application which you can expect to use for many years to come.