One thing to consider is royalty rate. If you sell 5000 copies for $20 and earn a dollar per copy, you've earned $5,000. (This math is based on 10% royalties on the publisher's portion, which is about half of retail. And no, fiction books don't sell for $20 typically, but I'm using this number to make the math easy.)
Now, if you sell 5000 copies of an ebook for $20 and earn 80% royalties, you earn $16 per copy, and earn $80,000. This is the royalty rate on Leanpub (disclosure: cofounder), but with Gumroad or blog + Stripe approaches you'd earn an even better percentage (if you want to run your own store).
For fiction, however, the dream combination is probably publishing in-progress with subscriptions. Currently it seems that Substack is the best for that. If you can get a few thousand people to subscribe for a few bucks a month, you could do well. The people at the top are doing really, really well: https://stratechery.com/2021/sovereign-writers-and-substack/
Now, if you sell 5000 copies of an ebook for $20 and earn 80% royalties, you earn $16 per copy, and earn $80,000. This is the royalty rate on Leanpub (disclosure: cofounder), but with Gumroad or blog + Stripe approaches you'd earn an even better percentage (if you want to run your own store).
For fiction, however, the dream combination is probably publishing in-progress with subscriptions. Currently it seems that Substack is the best for that. If you can get a few thousand people to subscribe for a few bucks a month, you could do well. The people at the top are doing really, really well: https://stratechery.com/2021/sovereign-writers-and-substack/