I called UA 1P line last week or the week before, to book my flight to HKG from SFO, and asked about purchasing a ticket using miles, they said for C it was 200,000 (RT)and 240,000 (RT) for F. Now I'm not sure they told me the right information, but I dont see why they would tell me something wrong.

So in the end, I purchased an upgradable economy ticket (H) and used 60,000 miles to upgrade (round trip--30,000 each way), which is what I usually do.