Just realized when booking some travel that I forgot to take action last October to prevent some mileage from expiring. As per http://www.ualmiles.com/ReinstatementMiles.jsp, it is possible to reinstate them within 18 months of expiry by paying $50 for upto 25k miles.
How should I value the cost/benefit to decide whether to pay this fee (I have another year in the grace period to do so) or just forget about the miles? As in, what is the minimum mileage where it would make sense to pay $50 for reinstatement.
If it makes a difference, I don't travel often but when I do, its either within the US or round trip of US-India(BOM).