I just bought my first official mileage run ticket. SEA-DTW-MCO-MSP-SEA. I leave on a 11pm flight on a Tuesday night and get back Wednesday night at about midnight. Miles with my Alaska MVP bonus is about 8375. Price for the ticket with taxes was $175 or about $.021 per mile. Not bad for a run out of Seattle.
My incentive for this is I discovered that a trip I'm taking to Africa using miles is 80K in coach and only 20K more for business class. A couple of quick trips to Florida for that upgrade is a great deal.