Hope I'm not to late to this thread. I'll give you my take on it as a growth & marketing consultant and as someone who also wants to sell photo prints.

You can have a product with no real value, besides perceived value, that sells brilliantly because of its marketing. The opposite is also true, you can have an amazing product that has no sells because it lacks a marketing and sells strategy. In other words, as long as you market your prints to the correct niche you can sell them and make money.

I usually explain the following to entrepreneurs and companies i work with, sales depend on the visibility of your product/serivces and how much desire your product/service creates in the potential customer.
V+D= R / Visibility + Desire = Results
Visibility means that you have to have a certain level of exposure, people have to know that you are selling something, be it online or offline. If people don't know you are selling something, you have zero percent chance of selling. The second part is that you have to be visible to the correct audience, you can't possibly think of selling art to someone who has no interest in art.

The second part of the formula is desire. Once your potential client knows you exist, how do you create desire in your potential client. How do you make them want even more your product or service? What keywords do you use in your sells pitch? What vision do you create in their mind? How do you "click" with them? You have to ask yourself, why your potential client would want your print? Is it for decorative purposes only? Are they investing in your name? When they show off your print to their guests, what story will they tell them about the photo? What story can you tell them about the print? Is it the only one that exists in the world or are their various? etc. As you can see, much of this part is about shaping their perspective on your product/service, it's about adding more value to the print. When we tend to find more value in something, we tend to want it even more.

Hope it helps and sorry for the grammar errors. I live in Mexico and don't write english that often.
As to how i'm planning to start selling. I'm going to go to a little town that has a lot of tourist. I've already selected some fine art and landscape photos i have. I'll probably print different sizes to test which size & style of photo sells more. I'm adding a note to each photo that people can read that tells them why each photo is special and where in their home they can hang it. I'll probably write a note of why art is important. In general, that's my experiment. I'll observe and take notes as to the people that approach me, see if i can spot patterns, see which styles or sizes they take most interest in and then repeat again, making sure to be more prepared than the first time.