What are the fees(charges)for use of an RSS supplier for a commercial site?
I am thinking of some of the major suppliers such as NYT, WSJ, AP,
Reuters, BBC, etc.

I would like to know, before I ask, what are the fees and
how the charges are determined (CPM, per click, per site traffic?)?

While we are a commercial site, we are not a very large one.  What are the
best and most cost-effective means to use RSS for a small commercial site using
an RSS feed from a major player?