I personally lik the kph30i more as bass on the ksc75 is essentially non existent, but you can’t go wrong with any. Personally I would recommend the shp9500 or the Samson sr850 over any of those cause the ksc75 and kph30i have pretty bad build quality and can break super easily.
That that kinda price? Hell yeah. At most you can just sell it on the used market for how much you bought it for or trade it with someone.