Market early-and this can be free Social Media, FB Groups, etc Also you can start playing with ADS. Start small and work your way up once you know what you are doing. I often do $1.00 day for 5, 10 15 days. AMS $1.00 a day netted me a profit in sales (minus what I paid for the sales) in my first year of advertising.
Write, what you want. The whole purpose of writing is that 10 writers can be given the same outline of a story and come up with completely different and fantastic tales. We don't need more folks writing to market. We need people creating and telling a story with their own unique voice. Sometimes those stories will fall "within market" sometimes on the "borderline" and sometimes totally "out of the grid".
All of this is great and needed. Don't let others (writers/editors/readers) control your story or your creative process. Listen, learn, adjust...but at the end write the story YOUR characters are telling you.
If you don't have talking voices in your head, leading you off your outline every once in a while...or even often, then your not doing it right! You can be a great writer, be 100% true to you and your characters and still make money (if that is your most important goal-who doesn't like money?)
I feel-a great story and some good marketing will always make you a winner, even if you don't follow the crowd. Stay YOUR course, do the WORK, and have fun! Also remember is a LONG race in the writing business.