I'm on the wagon with Radio Shack, i've found alot of items there that work for me.
My approach to budget is a little different. I'm always on the prowl, no matter where i go (dollar stores rock!), i look at everything to see if it will work for any modeling need, not just my current build. Close out sales and Discount bins are a good place. I also like second hand stores. I can pick up old electronics for next to nothing (radios, vcr's, tape recorders, old computors, broken toys, watches) you get the idea, they are loaded with wire, tiny screws and bolts, thin metal..endless possibilities if you use your imagination. I use aluminum cans. cut top and bottom, then down the side. it works for scratch building metal stuff.
Other than that, i'm just very creative, i use my imagination and modify items to my needs.
"Creativity" is the key word here.