Try auctions for a 24" washer/dryer stack. Particularly the ones at storage units. You might have to buy a whole unit to get the few items you want though. We work an auction a couple times a month for an auctioneer up in Albuqueque (We're the food vendors). We have picked up several things that way. Yesterday, we picked up two sizes of metal ductwork used to vent gas dryers. These are the same size as two of the three heater vent hoses used in the bus. Also got three sections of chimney stack. It was two box lots... total cost was under $17. The metal ductwork will go into the front heater (means we have to buy the small hose and maybe another section of the medium sized hose), the biggest chimney pipe section (3 ft long) may be reshaped to become the plenum for the bus rear heat exhanger (to be moved and mounted, mid-ship, under the bus), the two smaller pipes (actually one double wall pipe) are about 24" long and may be used as trash cans mounted to the kitchen cabinet sink door and the bathroom vanity door. A word about auctions... they take cash and some take plastic. Don't be too eager to bid. Have a price in your head and don't go past it. Wait for the bidding to slow down before you bid. Sometimes the bids will run up too fast and you don't want to get into the bidding wars. Got to a couple of auction and LISTEN to learn how the auctioneer speaks. following a fast auctioneer can be difficult. If your hearing is bad, take some one with you. Take some one with you anyway. It's good to have someone watching for what you are planning to bid on and you will also have help loading all that stuff that you hadn't planned on buying . Keep track of what you spend. Most auction houses will charge a fee based on how much you buy (the one we work for charges 10% and no sales taxes). Estate auctions are FANTASTIC. Don' t forget you are buying AS IS, WHERE IS! There are no guarantees that anything will work. If you need reading glasses then take them with you so that you can inspect things close up... you can buy a cheap pair of reading glasses at Dollar Tree for $1. Auctioneers do not always know what they are selling. If you do end up buying a storage unit full... you can always get rid of it on CraigsList (the salable stuff) and freecycle the other stuff you can't sell. With a little luck, you should be able to sell the stuff you don't want/need on Craigs list to recoupe your buying costs and hopefully your storage costs. Ruthlessly get rid of what you can't sell within two weeks thru freecycle.
How do I know this? We used to "junk". At one point, that was what we lived on and we did pretty good at it too. Once David bought a whole building worth of junk (church Thrift store) at an auction. We made the purchase price back in the first weekend of Fleamarketing and the balance was profit. We had a place to store it at the time that cost us nothing. While we were packing up, we were selling stuff off. We used to have a little 12 ft flatbed cargo trailer that we used to haul the stuff (you take them with you to auctions). We also delivered some stuff and made a little extra that way. Actually we still have the flatbed trailer. Most folks just wouldn't recognize it now.... That's it in the avatar!