Hello, I have recently been introduced to road biking. Prior to this I have been solely a runner. I am tired of running marathons and need something new and more exciting. Therefore, I am looking into purchasing my first road bike. I was wondering if it would be better to purchase a new bike at a lower level with lower level components or buy a used higher end bike for a similar price. I understand there is a huge price range among bikes and their frames and components, but I am just looking for some general answers. I don't have a preference about frame material but would like to have a minimum of shimano 105 throughout. Also, if it is better to go with a used higher end bike- how many miles is to many miles.