Suggestions on things you can buy with achievement points

My server has a, as far as I know, unique feature:
Achievements

we're working on a new version of the site, and we thought of adding achievement points. For example, if you've earned most levels in a McMMO skill in the end of the week, you earn 50 achievement points. Become a member and you earn 10 achievement points. This system is automatic, so it wouldn't be any work when the coding is done. Currently, the achievements only rewards ingame money.

Since users can login to their website account (connected with the ingame account), we're thinking of a page with things they can trade their achievement points for.

What I'm asking for, is what could the achievement points be traded in for?
So far, I've only thought about trading in achievement points for tp to coordinates, fly for 5 points per minute, and trade into money.

Is there a plugin that can create items that doesn't exist in the game? That way, they could for example trade 100 points into a special bow, or into a special sword. Achievements would be something to work for! If the items get a new item id.

All suggestions are appreciated!