Apple care related

You had 60 days (from the original purchase date) to purchase an AppleCare+ extended service plan. Unfortunately, too much time has passed and you will not be able to get AppleCare+ for your phone. However, you still have the one (1) year limited warranty that covers manufacturing defects for the phone.

AppleCare+ extends the warranty to 2 years, provides to incidents of discounted accidental damage repair / replacement, and provides 2 years of telephone technical support.

The standard warranty is 1 year, does not cover accidental damage, and provides for 90 days of telephone technical support.

AppleCare+ must be purchased with 60 days of originally purchasing the phone.

Then have your brother go through the process of ordering a new iPhone from the online Apple Store. Once he picks the exact model, he will be offered the opportunity to purchase the AppleCare+ plan. That’s where the cost will be provided.

The cost really isn't relevant because it's too late for you to purchase it. 60 days is 2 months. You can't buy it for a phone you got 4 months ago.