Ultimately, Hero Lab is an amazing tool, and in my opinion (which my differ from yours) you'll want the entire package as you go.
The cost is prohibitive as a lump sum, as it was for me... and I bought it years ago.
I personally took the main hard covers at the time... core, ultimate magic, ultimate combat and ultimate equipment as the basics, and bought those all at once.
Then added a hardcover or a couple of the player or campaign packs at at time, a little with each check (or mostly so).
Eventually... two or three years later, I had all of the available content. It doesn't have to be all at once.
The tool is amazing for building characters.
You can take an archetype for a class, and then click on valid options only (as opposed to all options), and see which other archetypes change/modify features that the first does not. Sometimes your build could have three archetypes, on the one class...
You could also use Hero Lab as a search engine. If you go to the trait section, on the feat tab, you could type in Fortitude and get every trait (that you have as a source) that mentioned Fortitude. Or if you want maximum initiative than type that in. Do the same for feats, archetypes, magic items. If you care about skill bonuses, for a Path of War build you can type in competence bonus to stealth and see what comes back.
In short, the more sources you have the better your database.
I basically said... I have "x" books, as HL sources. Our group had that many sources as valid options for building characters for the next campaign. It had to be a HL valid build. Now one of my players is trying a campaign, experimenting as it were, and his requirement is that our builds be Hero Lab legal.
Our group is now playing (still face to face, after 32 years of 10-14 hour sessions every Saturday) with a virtual table top. Having all of the Bestiary sources, I can export a monster with a picture and import it into the VTT. So there are uses for Hero Lab, beyond simple character creation, but it is absolutely superb at the character creation aspect.
You can search spells, for a bonus to whatever, and have all the hits. It is an awesome search engine for just about any build you want.
It is also a valid build checker, to see that everything stacks correctly. The same bonus types generally don't, but you can check various boxes to see if your Rage stacks with your bonus from your equipped belt. Or maybe if the Cat's Grace buff stacks with the belt too.
Overall, cannot say enough for how awesome the tool is.
Plus the community has a lot of friendly and helpful people if you're asking about the product in general or in how to use the editor.
And the company itself has amazing people too.
A+ x1000
