High end alloy wheelsets worth it?

is it worth getting good alloy wheelsets as an upgrade ? are they much lighter than stock wheelsets? I have RD 2.0 mavic maddux wheelsets on my Synapse carbon but i feel they are quite heavy..dont notice it on flats but on climbing i notice difference.

i noticed chinese carbon is very popular lately but can one get good alloy wheelset under $700?
disc wheelset in particular