Have no idea but the sale started right after Christmas. You can always call them on Monday.
You said you had $400 to spend on a center. $400 will get you 2 V5.2's if you don't have enough for a 3rd one right now. That's a least a good start. But if you really have up to $750 then you should get your 3 speakers now,.
I wouldn't wait long though. They had a sale similar to this on Energy V6.2 towers and they sold out quickly. Now they're nowhere to be found at all.