Estimates are that 80% of your energy is to overcome aero drag. So, aerobars are highly encouraged.

However, I'd not get that bike. Get a used tri bike (a motobecane tri frame just sold on ebay for $125 buy it now). You could have a very decent bike for under $300.

You just have to keep your eye out. Also, CL has some great deals. Get an old road bike and then get some aerobars like these or these

Dont pay $100 for a pair of aerobars until you know you like the sport and get more serious.

Something like this might be a good cheap base bike: http://raleigh.craigslist.org/bik/1515606849.html