$2200 buy-up offers to Global first on a TPAC flight: glitch or a decent deal?

I just purchased a ticket from US to PEK in economy K fare class. After purchase, I saw a buy-up offer that's about $2200, which gives me first class on all domestic flights AND "Global first" on the flight to PEK. Is this a glitch? I don't think GF can be that cheap.:p

Edited: in particular, for the return flight on a PMCO B772, United asks for $4000 for a buy-up to BF on a PMCO B772.