Ye, honestly, I can't think of anything you'd use a startup disk for these days except for a classic computer
For example, a dos diskette is almost worthless since most drives are NTFS these days. Anything else is pretty much available for CD startup disks. Need memtest? That can be downloaded in ISO form. Need a restore disk? Well, ain't no operating system this last 10 years fit on a floppy. Need a repair disk? That's on your windows disk already.
Check a small mom and pop computer shop tho, they'll have floppies if you really must have one.