Originally Posted by
i_gtgo
Thank you all for your valuable input.
I know the miles are good/active because he's been very keen on preserving them through credit card activity. He used to travel a lot and may have saved them for a rainy day but now sees no value in it for himself.
Gift cards will earn him around 1 cent a mile and I don't view that as a great deal. But I'm sure there are people who value it a lot more than that and would pay him for it.
If the relative using the miles is not hurting for cash, I'd suggest that a cash thank-you gift of 1.5 cents per mile used would be appropriate. That's the value I use for tax purposes when I use personal miles for business trips (another hotly debated topic around here).