i've got a mopar 727 stall and it's welded to the converter.
Stall isn't something that can be welded to something else. Stall isn't a thing. Stall speed is the RPM that the impeller in a torque converter has to spin in order to overcome a given load and begin moving the turbine. In other words, it's a measure of slippage.

You're apparently talking about a torque converter with a stall speed of around 3200 RPM. Most transmission/converter manufacturers make 727 converters that will bolt to an AMC engine.

It looks to me like you're comparing the price of a full race ATI unit to a standard street model TCI. Apples and oranges.