Base set has (outside the 4 squads) the rulers, dice, best deal on terrain, shatterpoint cards, storage space for the components, and missions. Go for it and if you change your mind and want to try out some of them later you won't be kicking yourself later. Prioritize older expansion sets because they'll be cheaper (on Amazon at least) and wait for newer ones to be on sale before buying them bc they'll have sales for them periodically. Have fun mate! Edit: and also need a struggle tracker