^ If you don't have any other issues or symptoms indicating the batteries are weak, I would absolutely not replace them until at least winter time rolls around. Your thinking in that 7 years is about or greater than the average life expectancy is solid, however other factors can increase or decrease the battery life.
Also, you don't need to spend $200 a battery. Many are that much, but there are plenty of FLA batteries in the $100 range.
Recently replaced the batteries in the Dodge. Home Depot has Exide batteries for just under $100/ea.
Can't speak to their longevity yet, but if they only make it half as long, they only cost half as much to begin with.
