FYI, I was looking at Ebay and have come across a auction with the following Esterbrook nibs: 2550, 2556, 2668, 1550, 1551, 9461, and 2314 B. Bidding is at $11.99 as of 12 noon Mountain Daylight Time. You might be able to snag a deal if your're lucky.
Here's the link: fp caps and estie nibs

No relation to seller, just thought this might be useful.

Donna