Digital BW, The Print

I was curious about what kind of densitometer or spectro I'd need to 
make my own profiles or modify what I already have.
If I just want to use it for BW work, using a mono inkset then what do 
I need to purchase?
I'm assuming I don't need one of the expensive ones.....

So what's a logical purchase?
I supppose I would like to know the price range as well. If it's 
the 'best' and costs a lot, what benefit would I receive?
Conversely, if it's on the lower end of the price range, what 
properties might I be giving up for the cheaper cost?

thanks 
Scott