No pun intended...
If Todd is a huge Rocky Colavito fan (he did spend 4 years with the Tigers, after all), then maybe having the bat signed may complete his vision of what he wants his collection to look like.
Having an exit plan on value is good, because we can't take it with us.
That being said, I can totally relate with Todd.
I collect Johnny Vander Meer and he's not a HOF'er either.
Maybe not a great investment with possible ROI like collecting HOF'ers, but as they say, collect what you like.