Hello, I'm relatively new to the commuting side of the cycling world, meaning I only really biked 1-2 times a month whenever I got bored but now I'm looking at commuting multiple times a week and I decided I should upgrade from my very low cost fixed gear. I've had my eye on a 2008 specialized allez elite in my area that I found on Craigslist, it seems to be in very good condition and costs 310$ (including a free helmet) but I've also been looking at a 1999 Cannondale T700 which was also said to be in excellent condition and cost 325$ (including shipping since it isn't in my area). I was wondering as a person with very little mechanical skill aside from replace an inner tube lol which would be a better option? Or would a brand new bike be better for a newbie like me? Since I'm new to this website I can't post the URLS but can anyone familiar with these bikes provide insight?

Also I'm trying to stay around the 300$ mark.

Go with one that will fit you. If both fit you then go with the Specialized. LBS is good too, but you will not find anything decent for that price range. Not even close. The Allez is a newer bike and valued reasonably. The Trek is overpriced.