what do you shoot the most of? start there. you can get a basic dillon setup (press, dies, and one caliber conversion) for under $500.
get a scale used for $30-50 (i have one i'd be willing to sell ya...RCBS Model 502 beam scale), a case gauge for that caliber (not NEEDED, but highly recommended), and a primer flip tray.
after that, all ya need is components.
i've probably got nearly $2k into my reloading room now....but i bought a little at a time...$40-50 here and there, with my presses (550B and a RockChucker) being the only real "big" investments. start small. you could conceivably spend $700 in components alone for those 3 calibers...
.45acp is a good one to start with too. VERY forgiving (it's a relatively low pressure round, and your brass will last almost indefinitely).
if ya wanna take a peek at my setup, depending on your location, you're more than welcome to come by and give the 550b a try. you REALLY cant go wrong with Dillon.