Actually, I think that is about right for install. I thought it was high at first but say the kit is 500 with tax. springs and shocks, then install is 3hrs @ $65/hr - your looking at 695 right there.
If you don't want to hassle, for the full install of shocks and springs that seems fair to me
If just for springs that seems way too high. say 200 for springs, 1.5 hrs + tax should be around 350 or less.