It's against the forum rules to sell airline tickets; however, only offering a $50 discount is laughable regardless, considering you'd be gaining 20k MR which have a conservative value of $350.
Who is selling airline tickets? I am offering to book a ticket for someone on my card. Why is it laughable? For someone without an Amex card it is a reasonable offer for CASH.
You'd be hard pressed to find people around here without an Amex card. FWIW, I'll offer $150.