Problem: There's a finite number of elytra on the server, so new players can no longer obtain them without buying off other players. Also, if existing players die and lose an elytra, there's no way of re-obtaining it. Solution: Add an elytra drop to the ender dragons drop table. It takes 4 ghast tears (among other items) to respawn the ender dragon, so it's still not easy to farm. My personal preference would be making the elytra a 1/2 drop chance to make ghast tears a bit more valuable. This would average 8 ghast tears per elytra, which take a while to collect even with looting. Additional idea: Could add a small chance of shulker shells dropping as they are also limited in number, although much more numerous than elytra.