Not purchasing, exactly, but more like gleaning.
A couple of months ago I tried something I'd read about: I saved the skins, peels and ends of the purple onions we were pickling, or using in pickling recipes. I dried them then ground them up in the blender. It made a beautiful and flavorful onion powder, purplish in tint, a full but sweet flavor, not bitter or pungent.
At first I was simply making it for Husband to use in his grill rubs. It's so good and so easy that I've kept on accumulating it. We can use it in soups, stews, casseroles, etc. It can stand in as onion flavor if we do not have actual onions. Of course it will never take the place of an actual onion but at least we can have the flavor.
Just yesterday I ran across a forum post from a home canner who was doing the same thing with her tomato peels, as she processed her tomatoes for canning. DARN IT, missed opportunity, I've already processed several many tomatoes! But I did process a batch of tomatoes today, steamed, peeled, cored and frozen to accumulate for canning recipes. The peels are in the dehydrator now. I plan to grind them up in the blender as tomato powder for soups, stews, sauces, etc.
Oh well on the missed opportunity. Those earlier peels went in the composter and fed the worms.
We recently pulled our carrots, sliced them thinly using our Kitchen Aid mandolin slicer attachment, and dehydrated those. Worked out well. A sink full of carrots reduced to three pints.
When we had devoted enough freezer space to summer squash we started slicing, spicing and dehydrating squash slices. It worked out well. The spiced squash slices are tasty as is, or rehydrated.
When we were overwhelmed with cherry tomatoes, we spiced and dehydrated those. Sometimes they do not make it into storage.
All of this was done with food from raised bed gardens in our front yard (fenced and sunny) and a second hand Nesco dehydrator purchased on Craigslist over 10 years ago.
Truth in advertising, the tomato peels are in our new, first 'store bought' Nesco dehydrator.
I've dehydrated potatoes and celery in the past and I really didn't enjoy the reconstituted product.
Right now I have a small amount of commercially dried green and red bell peppers, tomato powder, cheddar cheese powder, powdered eggs for baking, some powdered milk and powdered sour cream, hummus powder, and commercially dried carrots on the shelves. All of these are in fairly small denominations.
Adding the dehydrated peppers and a spoonful of tomato powder to the powdered hummus when reconstituting it, along with some granulated garlic, cayenne pepper, chili powder, cumin, chili oil and olive oil is divine.
Oh, and we also have home grown, home dried crushed cayenne peppers stored.
None of this is in the hundreds of pounds. Mostly I store in canning jars.
Prior to moving to this house, I had three (3) second hand dehydrators off of Craigslist for pennies on the dollar. I often had them all cranking when I was drying large batches (typically store bought apples and bananas.) We had a whole house, stand up attic with shelving in that house so I had ample storage. (In terms of cabinet space, dehydrators are space hogs, it's true.)
We don't have that kind of attic space here so I donated two of those dehydrators when we moved here full time.
This is the first year we've had a raised bed garden and I missed having more than one dehydrator, so I cleaned out some cabinet space and bought a second dehydrator on sale at walmart.com.
I did check several online resale resources first. Around here, used dehydrators are slim pickings at the moment.