Hobby-grade linear actuator?

This thread, where the OP there has deeper pockets (or perhaps corporate pockets....) than I and uses Firgelli actuators, made me wonder if there are any hobby-grade (read as: cheap) linear actuators.

I'm an engineer by qualification so I fully subscribe to the need for properly engineered and built components when it comes to moving heavy things safely, reliably, effectively and efficiently, but I do wish there was a cheap alternative to those commercial grade products, just to "play" with.

aliexpress seems to provide a reasonable choice.

It is quite easy to make a linear actuator from threaded rod, a traveling nut and a motor. Many on line examples, like this one.

Firgelli are the cheap hobby ones.