My most expensive MR was about $600: DEN-LAX-SFO-JFK-SFO-LAX-DEN. It really made me mad because when I first saw the price it came to $250, so I put it on hold. When it came time to actually buy the ticket it shot up to about $600. I know it is expensive, but I was having a really bad day so I bought the ticket to make me happier. My cheapest MR was $150: DEN-MIA-DEN. All of this was on AA.