re: if I need to purchase in order to set up our staff directory in a decent format.
This is subjective. Many thousands of users use the Default template as is and meets their needs well. So fo them, there’s nothing to purchase.
re: We’re a school and I’m hoping to have a list of all staff based on groups- Administration, Teachers, and Staff (alphabetically) with just name and title with the name acting as link to their pages with more info.
Display wise, I have nothing available that matches exactly what you describe. The closest are the Excerpt Plus and Slim Plus templates. I do offer custom developed solutions so one of these could be tweaked to meet you exact design requirements. Just let me know if that is an avenue you wish to pursue.
re: Currently I have a long obnoxious list of everyone (not by groups).
Connections can be setup to group entries but this does require a more complex setup that might be too difficult. What I suggest instead is to categorize the entries in your directory according to group. The category filter in the above mentioned templates will allow your users to filter the list based on the selected category group. Another method would be to put each group on their own page using the category shortcode option to define which group should be displayed on a page. I really suggest the former over the latter because it is far easier to setup and maintain.
re: Thanks for any help!!
I do hope my answers help. Let me know if you have any further questions.