Hi Andy,
Not entirely sure of what you are trying to achieve here with people uploading their image and then purchasing their own image but as you say I’m sure it all makes sense
There are actually quite a few ways to do what you need. If you just want to have people uploading an image and having it sent to you then you can use a multitude of options to get what you need.
First off you can use the EE CP Image Uploader with a Stand-Alone Entry Form but you would need to have the user logged-in to a member group. You could use the LogMeIn plugin which would allow you to automatically log people in under a certain user group which may or may not work for you as you would probably want to be retrieving information pertinent to that person at that moment but if you have custom fields set up for use in your SAEF then you can get them to fill those out and get what you need in that way.
The only problem in using the EE CP Image uploader is that people need to understand how to use it and they also get to see all the other files that have been uploaded which may or may not be something that you want to allow. Without modifying the core ExpressionEngine files then I don’t think there is a way around that.
A nicer and I think easier option would be to use something like Freeform which will then just function as a form where people fill in their details and choose the file to upload and it all gets sent off to you. Using Freeform in the standard way does mean that the information won’t get placed automatically into a weblog entry (not sure if you need that or not or whether you just need to collect the image and information?) but you can make it do it with some clever jiggery-pokery.
I am actually doing this on a site I have created by using Freeform to submit the e-mail to a moblog e-mail address and then the file gets uploaded to the destination I specify and the rest of the textual information gets placed into a weblog entry for me! Nice, simple, effective but extremely powerful.
There are a few other ways of doing this and a few plugins on the forum here to do just this but it would really depend on exactly what you need your system to do? If you could elaborate a bit more then I’m sure other people will probably have some ideas too to help you out with.
Hope some of that is of interest though
Best wishes,
Mark