Write him a long letter with some nostalgic anecdotes from childhood and teen years, but nothing where he actually helped you out, or vice versa. Then use the last paragraph to talk about your strong bond or how glad you are to be his brother and how proud you are of his accomplishments. If he has kids or plans to, you can probably save up and do something for them down the road. But don't try to overtly or immediately balance the books, guys and siblings are instinctively competitive enough that for this to work, one of you has to be the b****. Subconsciously he might just trying to brag about his job, so the best payback may just be to earnestly and convincingly show more of an interest in it.
