Mountain bikes need to have sturdy frameworks and highly durable tires. For beginners, a quality mountain bike that has adequate safety engineering costs less than $700. One may need to invest a few hundred dollars more for riding a professional quality mountain bike. However, the prices rarely go over $1,200. However, if the rider requires additional suspension, the price may go up to $1,800. For beginners who can afford, a great bike with good suspension makes for a good long-term investment.