This is what I would do:
1. Take a cool picture - free
2. send it to Australia to be painted - free, email it
3. have it painted - free, get the artist on board for a trial painting
4. have the artist send it back - small shipping cost
5. try to sell it.
If it works do it again and again.
As for price, just go out one day and act like one of the customers you are trying to attract, think like then, go to places they woud go. Visit other places that may sell something similar and get an idea of the prices, ask if they sell many, observe other buying them etc. That might help set a price, dont worry about getting it wrong forst time, that is what sales are for! :)
Good luck, I think it is a great idea and you should at least do one to see how it goes.
Blah Blah, really I wonder if anyone of these posters have every actually started a business, or spent time sifting through countless business proposals looking for funding. Or are they just selling their business plan writing services??
Yes some sort of plan is important but nowhere near a must have for a cracking busienss start up, there are many (millions??) of pretty ordinary businesses with GREAT busienss plans.
To revert back to the topic heading, starting with the right attitude is a great starting point, and something most successful entrepeneurers have. (and surprisingly some have very ordinary business plans).
My tip if you are starting your own business (like I have successfully several times)...be bold and get on the phone and sell your idea to anyone who will listen.
Good luck out there.