During the trash run I make every week at our trash/recycling dumpsite-see so many bagless plastivacs-and yes lots of Dysons,broken,dirty,and sad looking.Very rare to find higher end vacs-one time spotted a Kirby G5 buried under a few large old TV's-It was badly corroded,bag torn.Left it in the dumpster-already have a factory restored G5.Most of the vacuums bought in my area come from WalMart,Target,Kohls, and such.The vac place here sells Meile,Sebo,Sanitaire,used Kirbys-only those in good shape.Most have been the sold to the customer-used once or twice,customer didn't like the machine(Older woman)and traded it to the vac place for a lighter canister or Sebo,Simplicity upright.I scored a second Sentria 2 this way.The vacuum is in like brand new shape-and came with everything,including the box.
The ideas of finding things like dust mites,bedbugs,and other bad things in used vacuums is a concern-of course the first thing all of us do is replace the bags and filters and clean out the machine.Then the worries should be over.When I vacuum out the used vacuums I get with my NSS M1 confident the fan will destroy most of the crawlies.And I replace the M1 bag afterward.Some models of vacs for collections will only be available used for the most part-so cleaning them out is what you will need to do if you want the specimen.