Turbo's dont die that early... Sounds like whoever owned it before youtook shitty care of it... How you damage an axle is beyond me, unless you were off roading. Is it bad CV joints? $700 each is rape. You can get both done for abouthalf that at any honest shop. Depends on where they get the parts from I guess... But either way, $700 is too much. Get parts from:
www.getcoolparts.com
www.ecartoys.om
www.purems.com
www.ecstuning.com
Find someone/mechanic who will install parts for you off the books or on the side for less than $70/hour. or figure it out yourself, most things arent hard as long as you have tools.