Some companies selling software or libraries simply put their licensing model on their web page and be done with it. (Many also contain a disclaimer that there are volume discounts and special arrangements possible.)
Other companies (most notably those placing themselves in the "enterprise" market) don't disclose their fees, some don't even disclose their licensing model! When you are interested in their product and contact sales, you then discover that their price calculation is simply a per site / per developer / per core / per whatever thing and they could just as well have put that info on their webpage.
Can fellow programmers give me an insight as to why I have to exchange 3 emails and 2 phone calls with a sales representative to find out if a product even remotely fits into our development price tag? I have found that me (and some of my co-workers) are extremely reluctant to even evaluate a product that doesn't disclose it's costs up front, so I cannot understand why anyone would do that for "simple" products - that is for libraries and software that really doesn't have negotiated license fees.
Note again: I'm talking about single-installation software or libraries that are licensed per-site or per-developer and not about stuff that requires complicated licensing agreements.