I haven't seen it in person, but Daltile Artigiano, in the Roman Skyline color, might work for you.

These tiles are a little lighter than your pic but they are pretty: https://www.flooranddecor.com/tile-decoratives/villa-heirloom-aqua-porcelain-tile-100183334.html#prefn1=color&prefv1=Blue%7CGray%2F+Blue&start=35

http://www.homedepot.com/p/Merola-Tile-Chester-Acqua-3-in-x-6-in-Ceramic-Wall-Tile-1-sq-ft-pack-WNU36CAC/205072147?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-BASE-PLA-D23-Tile%7c&gclid=EAIaIQobChMIu9TWnMzt1QIV1zqBCh22Ww3wEAkYASABEgKRYvD_BwE&gclsrc=aw.ds&dclid=CJ-ozKDM7dUCFcFDNwod70QGPQ

Have you looked into Walker Zanger Cafe tile? The tile in your photo looks similar to their Water Gloss color. I was recently quoted $17.50/sq ft retail price. If your tiler has an account, I would imagine you could get that lower.

I've always been a fan of Fireclay Tile, and they have certain glaze/size combinations that come in at $15/sf including Moonshine in 3" x 6" subway tiles below, and Nickel below that. French Linen is one of my favorite greys, so if you place a sample order, definitely request that too. It has no blue in it, but it's a gorgeous grey.

I ended up with these, which was not my original idea, but I love how they look in my kitchen. They come in several colors.

Whisper