Wow looks great!!! I found a great tile site, I used to go to estate sales too but now I do most of my ordering online from Glasstiledecor.com - they are so cheap they have great brands, great prices and free shipping - hope this site works out as well for y'all as it does me - bc i am a mosaic nut! Here is a link that might be useful: glasstiledecor

It's a beautiful tile, but I wonder about how you line up the ridges when two tiles meet in a corner. Is one side of your shower more visible - maybe use this tile on one wall only? I would probably put a seam right in the center of either wall, but a good tile installer should be consulted before you order. We used large width Porcelanosa tile with a dimensional wave pattern in our 5 ft powder room - but on one wall only, and we did the seam in the center.

depends on the size of the tile. That tile in your picture is from AnnSacks (see link above) Chrysalis is a collection of hand cut and fitted artisan glass mosaics that stand out for their beauty and craftsmanship. .Mosaics are film face mounted. .Sheeted repeat sections will fit together in an interlocking system. It says it's film-faced. (which means it comes on a sheet_) But other tiles can come as individuals. this is a 4x4 some come on mesh sheets, some come w/the film on the front. (if the tile is somewhat see-through, like a glass, the film face is a better option since the mesh won't be visible. ) Floor and Decor has this glass tile, much cheaper than the ann sacks. https://www.flooranddecor.com/glass-decoratives/marina-del-ray-arabesque-glass-mosaic-100463090.html https://www.decorsmosaic.com/products/azure-glass-mosaic-tile-in-fish-scale-for-floor-and-wall-cgt012-99

OK, and your question is? Simple answer would be to go purchase more.