You may very well find yourself riding quite a bit more than 10 miles a day if cycling becomes your thing. And even if it doesn't, a few bucks spent upfront is still money well spent, since upgrading an entry level bike is almost always more expensive than just buying something higher spec'd to begin with. So consider spending a little more than you think you should up front to avoid spending money on upgrades later. Second, I would advise you and all beginners to get a bike a bit sportier than you think you need. With a few tweeks, it will be plenty comfortable for casual jaunts to the grocery store or into town for a coffee with friends, but will also be capable of 20, 30 or even the occasional 60 mile ride should cycling become your thing.

I understand a budget but, IMO, $450 to $500 retail (less if you can get something on sale) is about the lowest I would go and it isn't out of the question to stretch your budget a bit to $600 or $700 if you can swing it. The reason is that especially when it comes to flat bar hybrids, you get the most money for your dollar in the $500 to $800 price range.