EWR-IAH roundtrip next month, both flights with flat beds. M fare. Buy-up was $524 total. Took it and noticed that the fare booked into PN (no additional PQM's), which I didn't like since I want the PQM's. Spoke with an agent who confirmed that the buy-up was to a B fare, which then automatically booked into PN. She noticed that there was an A fare that was actually less expensive than the B fare. She rebooked me into A, which produced a $109 refund, making my net upgrade cost $415, or about $207 each way. My recent buy-up price on this route at OLCI has been $189 each way, so I ended up paying about $18 more each way to guarantee a good F seat now, as well as 2800 additional PQM's. (If I had left it as is, I might have gotten 150% PQM's for the B fare, but I wanted the 200%.)