the SAZ series are better than the SAE series.
(they have better internal components, basically everything is upgraded)
Of course if the amp is beat to all hell, then its not worth much. But if its in good condition, usually the new heat sink models go for $330
poor/mediocre condition, i've seen them go for $280, could get lower.
The newest heatsink model has saz 1500 written on the top and bottom of the amp's face. Other models only have it written once.
there is a new model of the sae1200 coming out, so the older ones are selling cheap as they're out dated.