Comparison/between/with/neither??

Hello,

Is the following correct? I have asked this question yesterday, but did not get a reply... I would really appreciate your help..

1) A comparison of training costs between senior managers and factory workers can be useful.

Some seem to use

2) A comparison of training costs for senior managers and factory workers can be useful.

3) A comparison of training costs for senior managers with those for factory workers can be useful.

WHich is correct? Are they all correct?

Which is used most frquently?

Thanks!

p.s. my question is whether using "between" or "with" or neither is correct.