Where to Buy Fuses for my OTL power blocks?

Blew a Fuse in my OTLs PSU(A single Fuse).
Can’t seem to find a similar spec online,

The spec is F 15A 500V.
Ceramic.

Company was Synergistic Research "Black" model.
They charge $110 for a fuse, About 110 times the price of a normal fuse...;-)

What is a sane, down to earth option.?


Thanks!