There is a media buying publication called the SRDS – Standard Rate and Data Service – that lists the rate cards for all publications and broadcast stations. It’s a paid service. What you pay for broadcast is determined by frequency, length of spot, and placement. It’s a negotiated cost. Likewise for the publications you cited – size of ad, color v. black & white, placement in the publication, frequency, all influence the cost. The value add that a media buying service brings to the table for ad agencies and clients is the ability to negotiate these rates and get a better deal. That being said, the SRDS will list everything. Otherwise you need to contact each publication and ask for their rate card.