just started recently taking the bike out for a run 2 or 3 nights a week and have caught the bug. My current bike is a least 20 years old, so wouldn't mind changing to a new bike. From looking at a few websites and shops the prices differ greatly. Seen one in decathlon for £300. All i want is to get out of the house and get fit. Don't want to buy a cheap bike and then regret it later. Need some advice please.