Offered only as a place to start looking. No experience with any of the slicers listed. I did buy a commercial microwave from them a few weeks ago. It was shipped same day and arrived 46 hours after placing the order via FedEx Ground.
I expect that an experienced meat slicer would feel differently, but as a person who has no experience with one this is not something I'd feel good about buying used unless I knew where it came from and how it was used/treated. I'd want to know that there were no parts missing and that it was reassembled properly after being cleaned. I'd also want to know that parts/instructions/documentation were easily obtainable for it.
One of these would be nice if you can find a used one in your price range. We have a supply house in town, but they don't carry used stuff and I've never seen an auction here. It is certainly on my wish list.