I've made several hundred fairy gardens over the years, and unless you make your own furnishings, nothing is "inexpensive". All of that miniature stuff is pricey. But I have found good deals at Hobby Lobby (using coupons or when they have 40% off sale), and a local craft store called Pat Catans, using my vendor card (stores in Ohio, PA and Indiana). Online I have ordered from miniature-gardens.com and several wholesale places, including wholesalefairygardens.com and jeremiecorp.com but you have to set up a wholesale account (must have vendor's license) and have a large minimum order. JoAnn Fabrics has some supplies early in the spring, but they sell out quickly, as does Hobby Lobby. I usually start purchasing in Feb. or March as soon as they start putting out spring merchandise. And believe it or not, one of the WalMarts near me had fairy garden kits in stock this spring, which included fairies and a few other miniature items like benches, etc. They were very reasonably priced. I did not see them at any other WalMarts tho.

Here is a link that might be useful: tons of fairy garden pictures

When I did mine, I selected only a couple of genuine "fairy garden" items. After that, I got most of my stuff at thrift stores and garage sales. You really just have to look at things in a fairy way to use thrift-store finds.

I use those small bath tiles as stepping stones. I made a fence from copper wire. I found some good stuff that was actually decor meant for fish tanks (bonus: it's already meant to be in the water!).

Most of the stores have all their merchandise for Fairy Gardens on close out about now. Doll furniture found at yard sales has helped me out more than once. Also look in the ceramic aisle at thrift stores. These little gems do not have to cost much of anything!!