Imo, go for a used autococker. I owned an AKP and i found it lacked the personality and smoothness of a custom built pump.
A decent autococker pump will run from 100 to 150 dollars for a decent setup, butnothing fancy. However, this opens an endless realm of possibilities and upgrades. At the same time, if treated properly, your autococker will not lose any value and you will be able to sell it for as much as you paid originally.