I think it shouldnt be just for donaters.. i am a VIP yes.. but i think minimal requirements should go to a trusted for survival. An at start for others. Its not fair to have to pay to donate items.
last time i heard from alex, "auction is for donator for reason, he also gave example: if we give vip and defaults then everyone will be rich in less than weeks" he decide to give only $15 donator player to use auc not for vip.
Not to mention the fact that if everyone could auction, the auction queues would be forever full and all we would see the entire time is auctions. I love a good auction just as much as the next girl, but it can be too much sometimes, especially if multiple people are auctioning off ten seeds for 2 mins. o_O