A few things to consider:
1. You can write and publish several books in the time trade publishers would take to reject your first book.
2. A publisher who’s giving a $5,000 advance isn’t going to spend much on publicity.
3. Odds are you won’t sell your first book to a publisher anyway. You’re likely to sell at least a few copies if you self-publish.
4. Most forms of book promotion don’t work as well as writing a good book and getting it into the hands of people who’ll spread the word. The days when you could sell a million copies just by posting ‘buy my awesome $0.99 ebook’ on Twitter every hour are long gone. So many writers do that that readers just blank them out or unfollow them.
5. If you self-publish a bad book, the odds of some irate reader stalking you with a chainsaw are low. The worst that’s likely to happen is that it disappears into the Pit Of Despair (aka the million-plus rankings on Amazon).