While BP isn't the best 4-hole option in baseball, he is solid and consistent, and has done a respectable job in the 4-hole previously. Also, if Frazier continues to perform like he did this year, he could easily take over the 4-hole and push BP up to number 2.
Assuming we can find a cheap LF option to provide a steady but not great bat in the lineup .800 ops type. Acquiring Span would improve the lineup quite a bit. I just do not want the black hole that has been CF and lead-off to continue, and I feel BP's bat is more valuable elsewhere in the lineup.
Now if we can pull of a trade for a young cheap clean-up type...I would be all on board, I just think a Span type move would add a lot as well.