Not really the best idea for a thread IMO.
1-It could put other members to shame at the fact they have donated so little in comparison to yourself and other members.
2-Some members could show off/boast that they have helped the site more and deserve more recognition/respect from staff/other members.
3-Posting how much you have donated in this thread is basically showing off that you have helped the site by doing this and others should recognize you/other members who have donated large amounts of money.
4-Sometimes staff positions can be brought with money. It has happened before. So by showing how much money you have donated,it could be implying that you are trying to show the admins that you deserve staff for donating a lot of money. I'm not saying you donated for this reason,but other members might have.
5-Just because someone has donated a lot of money,doesn't mean that they actually help the site in any other way.
Take me for example: I have only donated $10 to become premium,I have not donated a single penny more since I became premium,but I have help NGU in my own way by: Helping others,reporting posts,being friendly to other members and making good posts.
So just because most of us haven't donated a lot of money,doesn't mean we haven't helped NGU
These are just my thoughts on this thread,so don't take offence or anything cal