Sorry, I had to go out earlier and had to make that a quick post.
I have done a fair bit of mosaic, and a mate of mine's girlfriend is a mosaic artist.
She works in glazed ceramic tiles like your example but there are glass tessaere (think that's how you spell it) the type used in swimming pools as in the fish pic that are available from specialist suppliers in numerous colours.
My mates girlfriend gets commissions for all sorts of things from pictures like yours to table tops, bathroom floors and bath and sink splashbacks, even a headboard for a bed, street door numbers and shop front signs.
I can't tell you how she charges, but she has sold pictures about 14inx14in for about £100-£150. She makes them with smaller pieces than yours, and yours looks like it has taken some intricate cuts that might be time consuming and not be viable for time x cost.
She does more the type of picture below.
Try this link:
Rod Humby
Down the right hand side is a list of artists you can click on their name and view their websites showing the type of work they produce.
The British Association of Mosaic Artists site might have links to forums where you might get better answers to Art Mosaic questions:
Portal Homepage