J = Full fare Business
C, Z = Discounted Business Class
(I don't know what "I" is)
Y = Full fare economy
B, M, H, Q, V, L, T, K = Discounted economy, from high to low (K is deeply discounted)

9 is the highest digit you'll find, so that 9 could really equal 50 or it could really be 9.

If you see 9's across the board in economy, my hunch is your chances for an op-up are slim.