Authors are free do to whatever they wish in terms of publishing and contracts, but my advice is to never pay to have your book published. Pictured is a contract I had received early this year that claims they believe my book had potential as it "was deeply emotional and timely story", but yet wanted me to pay 5K because I am a not well known author.
A publisher should believe in your book, or they don't. Any business takes gambles and either they keep you or drop you in the end. But to spend money on things that you can learn yourself or pay someone will the skills to do so for less money and not get the exposure it needs seems backwards.
When I looked up the books that were published under this publisher, the Amazon sales ranks were all in the 3 million range. To give you a sense of how that works, if my book is in the millions and one copy sells it is usually catapulted in the thousands for a bit. That means the publishers books aren't selling and many of those authors paid money not to get close to any return on the investment. This is not their fault.
I'm not telling anyone how to do get their books out but after ten years of this I can only give advice. Things take time. Build your brand as best you can with the resources you have and don't let some "publishers" ring your wallet dry. There are a bunch of books in the world so make sure you find those that will fully support it because they believe in it, and not because they want your money.
You can buy Small Hearts right now by clicking HERE