If you have a local bicycle shop (LBS) that you have some confidence in, make sure you get the target bike checked out. Ultimately, what really matters is that it's a bike you *will* ride ... personally, I'd go with an old Gary Fisher (I've got one from the early 2000's that still is solid and quite ridable).

w.r.t. budget, make sure you budget for good lights, a bag (pannier, backpack, whatever works best for you).

You don't mention anything about your commute (distance, hills, weather, plan to ride all year...) so extra hard to guess what might work well for you.