The 'basic' exchange rate for points is usually 34.5 points per dollar when using points to buy Amtrak tickets. Last time I read about points, I think someone quoted 37.5 points per dollar for Acela tickets. And during holiday or other heavy travel periods, the conversion rate gets worse, eg, more points per ticket dollar value. It should be noted that using points for other Amtrak purchases such as lounge passes have different point redemption values vs paying cash for a lounge pass.