I just replaced the axles on my 2001 this saturday.  No core charge on the
axles, got them for about $70 each brand new.  replacement took less than 3
hours for both (I flushed the brakes, and replaced the rotors while I had
the wheels off, otherwise I'd have been done much sooner)

I'd rate the job as "easier than it sounds", check a chiltons/haynes manual

I was replacing the brakes on my GF's Elantra and saw that the outer CV
boots are torn.
Does Hyundai sell just an outer CV boot replacement kit, or do I need to buy
a whole axle assembly? my other choice would be to get a rebuilt axle and
turn in my cores I guess... The joints arn't clicking, yet.