Unfortunately I don't have outside storage. I've been thinking about getting a Rubbermaid or similar storage box, but I'm still not sure about storing something hazardous, and unusual in something that might be broken into.
When I first moved here 15 years ago. there were a pair of #%^&-for-brains kids living a few doors down ( long gone ) who were very good at "finding" things. (like ladders) I had some spent fixer stored in a 5 gallon cooking oil jug on the back porch with the idea of eventurally reclaiming the silver. Anyway I found in it the 3 foot passage way between my duplex and another wooden one, drained, and with a soggy burned out match book. These junior arsonists (or some of their friends) had tried to ignite it!
As far as yard sale finds, that one was a long time ago. You find a lot of weird things around here. I passed on the antique stomach pump at one of them. A couple of year ago I stumbled apon the moving (overseas) sale of a photo grad student who was ditching the last of her darkroom supplies.
$20 for a bin including:
a sealed 5 litre bottle of Ilford and quart of Permawash
3 SS tanks wityh good lids and 3 Hewes reels etc
That doesn't happen very often though. I missed the paper, probably Gallerie.