Whether the idea that selling some digital images feasible?

Several months ago, my girlfriend wanted to make a custom photo calendar(that's something that you can put your photos with some edition on a calendar). And we search for some tools for this kind of work. But I found the existing tools are too rigid, which just provide some templates and we should only follow the templates.

So I write a piece of software with Adobe Flex to help to make this kind of calendar. What the software do is:

1. A flexible calendar control;
2. A set of toolbox which can let the users to place/edit their photo;
3. A set of photo frame control which can let users to set frame for their photos;

Indeed, I think it is really a nice tool to help to make custom photo calendars. So, I just wondering whether I can make it as a online service and help others to make their own photo calendars.

Since I don't have any printing machines and I don't want to buy any because I am now only a student, ;) So, I am wondering whether to let the users to pay only a very little money to get all the 12-month images they produce use my tool.

I am thinking about whether my idea is crazy... Any advice and critics are appreciated, thanks!

This idea is not crazy, indeed i am working on similar idea but can't give you more details here (may be leater when it is ready :)
You can look first at competition and see what is already available.

A lot of people are searching for online (mostly free) service to create such calendars. It is probably good idea to combine such service with other services and to partner with some quality printing service.

Not a crazy idea. Maybe you could partner with other websites like artsonia.com. You provide the technology and they provide the order fulfillment.