sugest teh praices

So I will start selling commissioned photomosaics, but I have no idea with the prices... so I´m telling you to suggest a fair price for them. I´m trying to sell them cheap, but not too much cheap. So, do you think 6-7 dollars it´s ok?
You can have a look of the Photomosaic thumbs, to have a look of how they look when they are finished. Also I shoul tell you than the original files are so much bigger than the files I upload here, perfect for printing on a lot of different sizes.
They mosaics would be persolalized, you can really choose the images than would be inside, not the stupid, boring and random images than you are obligated to use on free photomosaic programs on the web!