At Mann Lake you can buy two kinds of honey extractors:
The first is more expensive than the second, and the second is waaay more expensive than the third option:
I can add the necessary fittings to make the garbage can look and function like the plastic honey extractor, but would like to know whether there are any garbage cans to avoid? Note that the can won't be used for storage, just processing of honey during the extraction process. Does this make a difference?
Other beekeepers have done this.
A heavy assumption may be that plastic container manufacturers produce both food grade and non-food grade plastic products. The process of switching between these plastics may be expensive to produce the different products may be expensive. As such, it's typically just easier to make all plastics food-grade quality.