Red Wings are the cheapest boots I'll put on my feet, but, since this is just a summer job as an intern, not as an actual construction worker, Cheapo's from Wal-Mart or Sears should do you fine. I actually hate steet-toed boots, and refuse to wear them unless it's a written job description, and my union rules state that if the employer REQUIRES safety shoes, they have to provide them or reimburse us a set amount for the purchase of them. (IIRC, Kahleeforneeya labor law also requires the employer to provide any required safety equipment such as safety shoes, but that may have changed under Ah-Nold) Nearly all my life, I wore these:
http://www.whitesboots.com/sto...?category=Boots&id=701 (for those who want them, they can be ordered with steel or celastic toes)
I have a pair in the garage that I had rebuilt when I got hurt, and are still in brand new condition...just waiting for me...However, for what you're going to be doing, they're overkill.