That's what I was afraid of, Richard. Tarikris, proceed with caution. As I said, self-published books getting legitimate trade deals is UNBELIEVABLY rare. Even those of us who've been around a long time can only name a few people this happened to (Andy Weir is the only one I know). There must be thousands of sales before trade publishers sit up and take notice, and I'm not exaggerating.
There's no harm in submitting if you want to see for yourself what happens, but the MOMENT they ask for money, toss everything from them in the trash and don't look back. Even if there's no mention of money, still be wary. Some vanity presses do have non-contribution-based sides, but the assumption will always be you paid to publish with them. You'll be more successful continuing with your self-publishing journey than tying your name with a vanity press.