When you are new to cycling it would be hard to judge the condition of a used bike. Thus I would recommend you head to a local bike shop and check new bikes. The shop can check and verify the fit and guide you onto something appropriate. You also get to test ride different bikes, which is very important. You're $1500 price range would get you onto an aluminum bike with decent components. As well you've got the shop to help with maintenance after you've ridden it a few months.