As others have said, check around. Look in local yellow pages for
sharpening, saw sharpening, etc. If there is a cabinet shop or
contractor available ask if they have theirs sharpened. When we lived
in Wichita, a local private lumber yard chain provided sharpening
services through a lady who lived in a nearby town. You dropped them
off and picked them up a few days later. When I figured out where
they sent them it was easy to check that town's yellow pages and I had
some done directly.

Where we live now, I am fortunate to have located a gentleman who does
excellent work and a very reasonable price. In many cases he provides
overnight service.

Word to the wise! When you locate a source, don't drop all of your
blades at once. Ease in with one or two blades, and if satisfied get
some more done. I responded to a "recommendation" several years ago
and the person screwed up about 1/2-dozen blades.