Stupid question but what would I need to buy besides the kegs to make this work.
Obviously a CO2 tank and a regulator. I guess what I'm asking is what is a bare bones setup consist of.
Thinking about maybe picking up one or two now and then getting the rest of the equipment later.
You'll need a tank and regulator like you mentioned, and obviously a way to keep the keg cold as well. You could do either a full fridge, a mini fridge, a manufactured kegerator, or a chest cooler with a temp control (a keezer). Those 3 items plus the kegs will be the bulk of your costs.
Next, for any of the setups you choose, you'll need some beer and air tubing, some clamps, a set of new o-rings, some keg lube, and a set of in and out ball lock connectors (or pin lock depending on keg style). It sounds like a lot but all together these items should be about 30 bucks or so.
Depending on your method of storage then you may also need a few more things. If you are using a pre-manufactured kegerator then you are already good to go. Otherwise you'll need a draught tower with a tap for a home made kegerator (60 bucks or so on eBay?) , or a tap meant to attach to a flat surface through a drilled hole for a refrigerator or keezer (maybe 30 bucks?) .
BUT... If we're talking super bare bones, all you REALLY need is a keg, a tank and regular, some place to keep it cold, all the same small items, and a picnic tap (like you see on kegs at frat parties). It all depends on how much you want to customize your setup. If cost is a concern, I'd watch Craigslist for things like used kegerators. I see them in the area all the time for 150-200 bucks. I wouldn't buy the expensive bits at your LHBS because they jack up the price on stuff like that. EBay and Craigslist can be your best friend! Good luck.