Climbing buttons are RD only as supplied. In theory one could use the Etube soft ware to reprogram a
climbing button set up to shift the FD but no one has commented on this particular mod. ie the
shimano etube literature seems to suggest this might be feasible. dunnoh....

As to cheaper, maybe $50-150 but rigging the buttons would require some compromises on a drop bar
and how acceptable that would be is problematic. On a flat bar it is great IME.