Is it possible to purchase a one-time update to the 430 database using the
Skybound adapter?

I don't fly enough IFR to require a current database year round and I'd like
to just update it during certain times during the year.

When I check their webpage all I can find is a one time mail in option using
the classic option, but the only skybound option is an annual subscription
which I don't really need. Why don't they have a one time deal like garmin
does on their webpage?

Thanks.