Could you throw out a few options? Then the peanut gallery could rate them
Second hand is the best value, new is... new. I wouldn't get less than Shimano 105 (as I said above) and I would insist on a carbon fork too. Beyond that, while I haven't ridden many I would guess that the big brands are much of a muchness at that price range ---> the main difference is whether the (somewhat) harsh ride of less expensive alloy bikes is ok for him.