Talent and marketable are different subjects.
It is not hard to spend a lot getting a book out there. There is only so much market action in any field, and publishing is about making money.
The cheap route, self publish 1500 the smallest print run, about $10,000, and you have no marketing.
To build a market, you send copies out, maybe several thousand, to book reviewers, library buyers, and book sellers. Now you have to sell 5,000, invest $50,000, just to see if it sells.
Most fields are dominated by names, and it is hard to start a name.
Having a story is only part, font, layout, editors, artwork, all go to make it fit one market.
The deal is also on consignment, you supply enough to put two in each Barnes & Noble, Borders, and if they sell, you replace them. If they do not sell, you pay to ship them back. Now maybe $100,000, and still iffy.
Writers sell books, you do signings, talks, TV, the Keton Kansas book club, and hundreds of small towns. You supply press releases to the local paper, buy ad space, have a stock ad, and it takes a lot. You go to every writers conferance, anything Sword-and-Sorcery related, vidieo games, D&D, and it all costs.
If it is your field, you read everything, and then track the writers, it is called stalking. If they are speaking, signing, you try for some space. You want to meet these people and have them remember your name.
At the same time you have to keep writting. You are writting for a readership, and a publisher, they have both, so you have to break some new ground that could make that publisher some money from their customer base. They are not going to replace a name with a new kid for the same demographic.
You have to understand the business enough that you can speak of bringing in market sectors that orher publishers have a light hold on, and your work will bring in more. They need to build long term, that new book is $50,000 out and they want readers waiting to buy.
Once it is rolling no one wants to stop, Jean Aureal wrote two good books, and the series ran seven, they wait in line for the latest Harry Potter, and can now afford teams of writers to produce it. When it comes out there are stacks at the grocery, the drugstore, for in a week or two you could not give it away.
I work small market sectors, selling fifty to a hundred copies a year works for me, I have three, more coming. I learn as I go and it does cover costs.
I have a big book, a lot of work, more to go. I think I have to sell thousands just to show it will sell and get a major publisher. If I can sell a few thousand they can sell a few hundred thousand.
The first book is hard, then you have a track record, and should have some manuscripts waiting.
Keep writting.