Do you sew yourself? Why not make your own? If you don't own a sewing machine, then hand sewing with small fine stitches would be just as good.
You'd just need to pick yourself out a nice piece of fabric, you don't need to buy a full metre, most stores will sell a minimum of a 25cm piece of the full width which would give you plenty to make at least 8 I reckon. If you don't want all your decks in the same fabric print, you could sell or gift the others.
Or try the cheaper variety stores as Gregory suggested. Especially this time of year they usually have a wide range of colors and sizes, mostly in organzas or light velvets, with a print or plain fabric, plain or embellished already. I found a gorgeous bag for $2, cream organza with a beautiful beaded butterfly on it already, it holds my Hanson-Roberts deck. If you go for a plain one, then you could always dress it up yourself if you wanted with sew on or stick on gems, or you might find delicate lace pieces to add to it, butterflies hearts and the like, or little charms and beads.The possibilities are endless and only limited by your imagination more than your level of needlecraft ability.
I generally make my own, picking the fabrics to suit the deck. My last one was for the Pirates Tarot, and as I sew quite a bit, patchwork and embroidery, I raided my own stash as I do for most of mine. I'd bought pirate themed prints for a project for my godson, so the bag has prints that feature skull and crossbones, a treasure map, rope and pirate flags in their motifs. I actually had more fabrics to choose from than I needed for the task! I finished off its cord with some beads, a la Jack Sparrow(sigh) and cut a square patch of a single skull and crossbone and stitched that to the front. I even had a skull and crossbone bracelet that broke (weak cheap alloyed metal) so I used one of the skull links to sew on it as well for an extra touch. It occupied me for a couple of hours one afternoon and it looks fabulous.