How to Know if A Self-Publisher is Scamming You

Are there only two choices? Can you risk working with a self-publisher that requires payment while trusting they will do a good job or publish with the traditional presses that offer declining revenue? You can self-publish; many established authors market their material so that they can guarantee full control. This can be very difficult, and it leads many authors to wonder how to pick a publisher that charges and provides good offers.