Everything related to PC is expensive... I have couple PC's in our household, no need to upgrade for another 3 years. Hopefully by that time, price comes down...
I think it is just because ram prices went up so much, pc sales are likely to fall and those still buying are willing to pay more. So they are effectively trying to cover up loss in quantity with higher margins.
Because let us be honest, unlike RAM, CPUs and quality PSUs, pc coolers is something anyone can make. These things are mass produced in china by the dozen.
A cpu cooler is just a block of shaped metal with a fan.
A water cooled is a bit more complex needing a pump and tubes, but the most difficult part is keeping it from leaking than making it.