First off, once you decide that you like the game go ahead and buy the second Core Set. You'll really want it for competitive play; it even makes casual play better as it tends to make it less based on who drew their one or two key cards first.
Second, go ahead and buy sleeves for each side so that you don't have to worry about cards getting beat up, bent, etc. You'll want to put your Objective and Affiliation cards in different sleeves from the main deck cards; additionally, the LS and DS cards should be in different sleeves. For the DS deck cards, I recommend buying 300 Black Dragonsleeves. For the DS objectives, affiliations and Committed to the Force cards I would recommend buying 100 of the FFG Force Lightning sleeves. For the LS deck cards I recommend buying 300 of either the White Dragonsleeves or Silver Dragonsleeves. For the LS objectives, affiliations and Committed to the Force cards I would recommend buying 100 of the FFG Lightsaber sleeves. I recommend 300 sleeves for the deck cards as for each side you will want to sleeve 18 objectives twice (18*2*5=180); then having extra sleeves just in case is always nice. Additionally, I recommend 100 objective sleeves as those sleeves will not likely be reprinted much and you'll want a lifetime supply of them. As well, I would recommend getting some 1000 or 1500 count boxes to store the cards in.
Third, I strong recommend having glass beads to use instead of the cardboard tokens. My preference is to have roughly 20-30 opaque white glass beads to use in place of focus tokens. I prefer to use roughly 10 light blue glass beads in place of shielding tokens. I really like to use 20-30 red glass beads in place of damage tokens. I find that the glass beads are far easier to keep track of, add and move on/off cards.
Total cost: $133-175
Base/Core Set x2 = $60-80
Dragonshields x6 = $50-60
FFG Shields x4 = $16-20
Glass beads x3 = $5-10
In interest of full disclosure, I am not an employee of Star City Games, Troll and Toad, Fantasy Flight Games or any other company which makes product to which I linked. Neither do I gain any sort of commission from any of the links I used. Links are solely for clear reference purpose and I am not recommending or discouraging people from buying from one site or another over the FLGS, FFG's store, or anywhere else.