Mosaics are more expensive than field tiles because of the extra cutting, finishing and matting. Smaller mosaics *can* be cheaper than larger mosaics because they are most often cut from the waste generated from fabricating 12"x12" dimensional stone tiles. You get more pieces out of the waste from smaller tesserae.
You will find that it can be less expensive to buy 12"x12" (most common size and so the cheapest to buy) tiles of the stone you are considering and cut the mosaic pieces yourself? Even if you have your installer cut all of the pieces, you can still sometimes save money over buying the mosaic pre-assembled AND you'll have a very unique installation.
Here are two examples of when I've been asked to make my own tiles to suite the customer's design.
This first was a French limestone from Ann Sacks which had been discontinued after the tile for the house's flooring have been purchased. This fireplace was an afterthought and the client wanted "something" which tied the fireplace into the flooring. I never throw away my cutting waste until after the job's wrapped up so I went through the piles and sorted by colors. Then I looked at the dimensions I had to work with and pitched this concept. The client loved it and I was able to give her what she wanted and we didn't have to spend anything on additional tile.

This next one is a curbless walk-in shower I built recently where the designer wanted to use a combination of 12"x12" tiles and 3.75"x3.75" tiles of the same material, but the smaller tiles weren't available in this stone. For this shower I cut a bit over 1,200 3.75"x3.75" tiles, which only took me a day to accomplish. Again, a unique product and considerable savings as similar stone in the dimension the designer wanted were more expensive.

Best of luck,
Shaughnn

Hi,
Thanks for the advice but I think I'd end up paying much more in labor than the price difference of buying pre-made large instead of small.
I am just hoping to either find the mfr or one who makes something close enough and charges a reasonable price.
I think the tiles I saw were 2x4 instead of the more common 1x2 used in most basketweave mosaics.

Ah! I imagined by "larger basketweave" that you were wanting to use a 4"x8" basketweave pattern or something similar.
Best of luck!,
Shaughnn

What was the price you were given?
You can buy direct from Amazon searching for product number: B00EQA4MDG

If you are in the Tri State Are, you can also buy in person. Location is in northern New Jersey.

Here is a link that might be useful: StoneLiquidators.NET!

shaughnn , I love the shower wall with the 3x boarder and the larger diagonal tile. I normally don't gravitate towards the diagonal wall tiles, but the mix you've created is really nice. I like the differing sizes and layout, while staying with the same color. Very visually interesting.