After a summer of borrowing gear or climbing on partners racks I started with:
-1 set of BD nuts
-Metolius TCU #1 and #2 (I recommend the TCU in the smaller sizes)
-Metolius Power Cam #3, #4 and #5
-#1 and #2 Camalot
This is the perfect balance of what you need to get started and not breaking the bank, imo. Over the subsequent years I picked up:
-#3 and #4 camalot (which I rarely place)
-#1 and #2 Rigid friends I picked up at a gear swap and had re-slung (doubles for finger size cracks)
-#8, #9, #10 and #11 Hexentrics (picked up at a gear swap)
I LOVE my hexes!!! Great way to double up on larger sizes without breaking the bank or weighing you down on those alpine approaches. They also provide a secure placement where nothing else will (like inward flaring cracks). Just put a long sling on them. Nobody has mentioned it here yet, but I know alot of people like tri-cams for this same reason. Pink seems to be a popular size.
Good luck