Is a $150 espresso machine actually worth buying?

It depends on expectations. Across reviewers, sub-$200 machines like the CASABREWS CM5418 and Chefman CraftBrew can produce drinkable espresso and decent milk drinks, but they rely on pressurized portafilters, have weaker steam wands, and won't satisfy buyers chasing café-grade shots. They're a reasonable entry point if you're milk-drink focused or testing the hobby.