Hi Ryan just purchase new , don't think that second hand will be cheeper !
By the time you get something second hand , strip , sonic bath / hydroblast , new gasket kits ect then you find they have been modified/messed with and the shaft's & butterflies are stuffed , blocked passage ways etc !
I did the above with a set of 44's that cost $1500 , a couple of hundred less than a set of new Weber's at the time and ended up spending close to $3.5k without air filters .
New Weber's will work out cheaper with out the headache's .
Just my 2 cent's
Doug