It is a flat 30%. It had been 25%, down from the 30, than they increased it back up to 30%. Some days it is not available and I don't think anyone really knows when it will end. It's a gamble to wait honestly. All of us that have used it think about waiting, but don't want to miss out on the savings.
Funny though, according to my eBay account, 7 people are "watching" the sale. Why would anyone watch a "buy it now"? Odd, I could see an auction, but not a buy it now.
I'm actually surprised this isn't sold yet. My Tamron 70-300, which was mint, sold in literally minutes. Too bad eBay fees are so high or I would have lowered the price for the Buy it Now.
If you do register, make sure you use the same email for the live.com, paypal, and cashback accounts. I helped a co-worker the other night get set up in 5 minutes and he saved $114 on a snowmobile helmet. He was pretty happy
