It looks like, while we're still discussing the pen, the biggest step forward would be for someone to contact an engraver and determine approximate costs. Did someone say they knew of such a person?
I have to confess, I find the M200 (or even 150 such as the Katie Hill pen) to be very enticing. I've never gotten my blue marble 200!

But there are obviously a lot of Lamy fans here. And the idea of a similarly engraved Lamy also appeals to me.
I wonder - does it have to be *one* pen then. Since this is not being done for profit to the group and the point seems to be to have fun and have a special little pen, then the ability to choose between a couple of pens might be even more appealing to the group as a whole. We're not going for an LE here that is so exclusive that only a few people will buy, right? At least, i think that is somethign we want to avoid.
Depending on the number of pens and the seller, we might be able to get a slight discount - say by including their business card and a short blurb on their support of our endeavor?
Does anyone know if Chartpak would sell to a group like ours if it's a "bulk" order. I
thinking out loud here.
Things to consider: The Lamy does have a unique grip which some find very comfortable (me) and some do not. The M200 is smallish, but comfortable for many folks at least in the short run (for me they're perfect), the M150 is a bit smaller and while this is fine with me, it may limit it's appeal (though it's also usually a bit cheaper I think.)
I believe the first pen shown by Tom? was the Sheaffer Javelin (of which I know nothing) - did that generate any interest?