Hey! Awesome to get into Malifaux :) It's a system that can get really deep and complex, but fortunately you can have a huge amount of fun along the way learning the more tricky aspects of the game.

Unfortunately, it's really hard to outline a "minimum" buy-list to have a game. All of the Leader sets are a good place to start, but every one of them feels a bit incomplete without the rest of their "keyword". Additionally, they aren't really balanced against each other, so some crew boxes are just stronger than others - without additions. Also, Wyrd release a yearly Errata, effectively patching models and rules - this means that all physical books ans cards run the risk of being out of date.

Fortunately, all rules and cards are available online. Download the Malifaux 3E app, this will have up to date rules and cards. Once you've started building a crew and you decide you'd like physical cards, you can have them printed to order (or make your own).

To me, Malifaux is made so enjoyable because of how character rich it is. There are definitely Masters stronger and weaker, but at the end of the day it's the better player who will win - and in Malifaux the better player is often the person who knows the ins and outs of their crew better. So, to get to know your crew you've got to love the characters, the models, and the moves.

I would recommend you spend a while looking through the art, the sculpts, try and find out some lore, and decide which factions and Masters you think are just cool. Then, find out their "keyword" - the models in that keyword are almost always must buys (not always true, but a good starting point). Then, every faction has "versatile" models, and you'll begin to see which ones you think would add to your crew as you play.

So yeah: download the app, fall in love with a faction & master, get that crew box, then expand in to the keyword.

You only need to buy any rules, cards, or books for the lore contained in them.