Few garden catalogs in my home offered options, and they were in the $20 or more variety - far exceeding my budget for this little experiment. I asked online to my fall gardening group, and they offered varying advice, including double-bagging them in Ziploc bags and putting them in the freezer. (I suppose seeds in the "real" world can handle a freeze or two.)
And then I stumbled on an article on making seed packets, which is an incredibly easy thing to do. So my oldest entertained herself for a few hours designing custom seed packets for our squash and bean seeds. You can find a kid-friendly template here. Want a "grown-up" version? Download a template here.