My alternator went out, I was quoted it would be about $600.Is this about right?

if u can get it to running disconect your hot post from batterie if it remains running its you batt that is bad

Your local auto parts store should have a way to test this without taking anything off, provided you can drive it there. My alternator on my 1992 ford taurus was going out, had it tested, took it off and got a rebuilt one from a local shop for around $100, put it back on myself, took 15mins but cars are differant as to how they are set up.