I do not know how I missed it all this time, but apparently doityourselfchristmas.com has sub-forums dedicated to specific elements and most have a lot of posts showing what methods people are trying to accomplish similar elements. This is really amazing. Unlike websites or blogs where you see how one person made something (like Matt’s youtube walk-throughs), you get to see a myriad of approaches to the same task. It really does open your eyes to different materials or designs that could be used, which might fit in your budget over other designs.
The display items forum page can be found here. Everything from people working with coro (corrugated plastic not dissimilar from cardboard box structure) to mega trees, arches, wireframes, matrices, and even motorized elements (which it likely not something I will tackle).