How many vacuum bags will I actually get through?

On general workshop use, a handful a year — on renovation work with plaster or cement dust, one or two a day unless you run a cyclone separator in front.

Bag consumption is dominated by fine dust rather than by volume. Sawdust and general debris fill a bag slowly. Plaster, cement and sanding dust blind the bag long before it is full.

This is where a cyclone separator changes the arithmetic completely: it drops most of the material into a bucket, and bag use falls to a fraction of what it was.

Before choosing a machine, look up the price of a pack of bags for it. On some models the bags cost more over five years than the vacuum did.