How much weight can a mid range stepper motor handle?

Basically I want the motor to push up a certain weight using a leadscrew to drive the weight upwards.

The information is that the motor will not be constantly operational all the time ie it will be idle more than operational for upwards lift and fine adjustment ofthe intend load.

This is for my project that I wish to make with a view to selling them on ebay and dependin how well they sell?