Seems to be the way with a number of headphones, HD650 we’re out at $500 and now exact same thing on drop for $200 for ages, though now crept up to $220 recently. Likewise for 660s and so on. But yeah price has dropped magnificently, I picked up a pair of the AKG712's for around £160 from the rainforest, drop down to that price now and then. Sold the second paid off for a handsome profit as they really do seem more expensive elsewhere 
IMO love my AKG 712's, but the HD650 / 6XX are the better all rounder. For gaming the 712's are slightly ahead though (though I tend to use my HD800s now for gaming more so), but if I had to pick one and stick to it, HD650 / 6XX all the way.
Yeah, it is frustrating in regards to the creaking noise which develops after time. Recently tried a friends new combo he picked up including 701 and so bliss with no creaking and when its brand new! I do suspect its very much does to providing additional flex for to allow more comfortable mounting on peoples heads.
IMO love my AKG 712's, but the HD650 / 6XX are the better all rounder. For gaming the 712's are slightly ahead though (though I tend to use my HD800s now for gaming more so), but if I had to pick one and stick to it, HD650 / 6XX all the way.
Yeah, it is frustrating in regards to the creaking noise which develops after time. Recently tried a friends new combo he picked up including 701 and so bliss with no creaking and when its brand new! I do suspect its very much does to providing additional flex for to allow more comfortable mounting on peoples heads.