There is not a right answer on this question and i am going to explain you why. Practically the answer is it depends on so many factors. What is your investment will be, what your experience and knowledge are? How much do you want this to be a success, how long will you last is things are not easy, what are the prices, marketing, traffic, ad spend , relationships with your customers, and how does the market will see your product?
I know these all can be frustrating. And they really are. You have to fight a lot in order to make money with a print on demand business. You must know what you should be doing and how to do it. And actually there is not a perfect plan. Everything goes see and adapt. This is how most of business go. If you would now it is going to be a success then everybody would be doing a print on demand business just for profits.
But you will ask who am i and why u tell you this.
I have been a print on demand business owner for 12 years plus making and selling my own products every day, such as wall stickers and canvas prints. Print on demand products are a great product to sell online but it is not that easy as you might think.
See some proof of my work to get better understanding
Print on demand is not a get rich scheme, but it can be a long lasting job if you want to follow.
You must be an expert at some point to do this job, such as graphic designer, or large format printing specialist.
But i would tell you if you want to do it , do it. It will be a great experience and you are going to uncover a ton of things.
There is no way you will not get a sale. The hard thing is to become profitable.
If you believe i could provide value please check the section work with me to get a better understanding of what i could help you with.
You will find a ton of information on print on demand on my blog and you will get a better understanding on building a profitable print on demand business.