Finally, you would then append the all caps disclaimer.
We have one seat at a table of four for dinner at Per Se this Saturday night, May 26. The first person who posts to this list that they can commit to attend and pay one-fourth of the total bill (including wine, the Per Se service charge, and $20 each to support the eGullet Society) is welcome to join us! Please post here if you're interested, and then I'll follow up on PM. Thanks!
Of course, if for any reason you don't wish to make such an offer available to all members, you can always use the PM system to get in touch with particular members that you would like to invite.