I need to book an economy flight from DEN to TYO for next week. United wants $2,343 for the non-stop UA flight. Expedia sells the same flight (with one night hotel) for $1,796 as a "special fare".

Am I correct in understanding that the Expedia ticket is a bulk fare that earns PQP? If so, is there any reason I shouldn't buy the ticket through Expedia? By my calculations, the Expedia ticket would earn 2,314 PQPs (11,574 miles / 5) versus 2,244 PQPs for the United ticket.