My Pilot Explorer post here remains one of the most popular on the blog. I didn't realize how popular this pen was. It's also probably the number one email I get asking where to buy these.
And after searching through some pen sources came up empty... I found them on some warehousing and random stores.. And I found some more this morning at a reasonable price.
No affiliation, and I don't know how many they have, Just passing along the info if you want to pick up a good pen.