I am interested in purchasing a road bike, 54-56 inches, preferably carbon fiber but am willing to listen to aluminum sellers. If you have a bike for sale that would be good for a new road biker doing his first triathlon in May, please reply!
Aluminum is a good frame material. Don't let anyone tell you differently.
+1 to what jbrez said. I raced on an aluminum road bike with clip-on aero bars for three years, including one Du-worlds and a 1:02 bike split at nations.
I have a 56cm 2012 Trek 1.5 Black/White that I may selling for the right deal. It is an aluminum frame but in very good condition. If you're interested, I can send you some pictures.
I strongly recomend you talk to a bike nerd about the frame size before you buy. Comfort is first before all other things. You will be disappointed if you get a great deal on the wrong size frame. However, if you are guessing, you are better off going a little big vs. going a little small. Good luck.