The thing to remember about self publishing (paying someone to publish it or publishing it for free) is that marketing is entirely on your shoulders. Companies that offer self publishing just make the book available, they do not promote your book in any capacity. That is the responsibility of the author and always has been.
Having said that, there are agents and publishers out there who do take advantage of aspiring authors, charging countless fees to make their own income while doing nothing for you. If this publisher is asking for more money, then I would advise taking your book elsewhere. If it was a one time fee to list the book, then it sounds like a normal self publisher.
The kind of system you're looking for is the traditional market, where a publisher puts in an effort to market your book. To get into that you'll have to find an agent. Personally I recommend the 2014-15 Guide to Literary Agents. It gives you all the info you need along with a list of agents who are looking.