Road bicycles are available in a plethora of styles and associated price tags. You don't need to purchase a professional-level racing bike to get a well-performing steed. Mid-level road bikes use high-end materials and reliable components to give you a great ride without breaking your budget.
Carbon fiber is ubiquitous in the professional circuit, but for a mid-range bike, the slightly heavier aluminum frames shine. These frames are durable, resistant to corrosion and offer exceptional damping against road vibration. You can still get an aluminum frame in a compact racing geometry if you're getting into competition, and an aluminum frame comes at a fraction of the price of carbon. The stiffness and durability will provide a fast, responsive performance.
The best mid-level road bikes use a good set of components to keep you shifting and braking smoothly, even if you abuse your bike on training rides and daily commutes. Your wheelset should be made from aluminum rather than carbon fiber as well, since these wheels will last longer and cost much less without adding substantial weight. A good-quality set of tires will make a big difference in your rolling resistance and traction, so it's worth investing here.