I own a few German-sourced pieces of equipment (Wallner darkroom gear and Multiblitz lighting). The small 5X20mm fast or slow, glass or ceramic fuses had proven awkward and expensive when I had needed to buy or order locally in my rural area. I recently found a nice, easy, fast and inexpensive source that others may find useful.

http://www.taydaelectronics.com/

Tayda Electronics. I rec'd what is likely a lifetime supply (okay, I'm pretty old) today and got some old, parked equipment up and running again. I ordered 7 different fuse types and they ranged from 18-32 cents each with a very moderate flat shipping charge. Anyway, I wish I had known of them before and am posting this in case it helps others locate these things. If other sources are known, please post them, too.