the yellow circle looks like a gem. i would see if micheal's has any big rhinestones.
Not like that they don't. You can make your own by casting resin and adding silver foil to the back of your gem when it dries. Some individual cosplay commissioners will make these for a small fee. I do believe that AmethystAngel does. She's very good at making resin gems.
Another option would be to track down a gold ornament of the right side. You might strike it lucky at Goodwill or Value Village, but if this is for Kumoricon, the Christmas decorations should be out in Michaels at the very least, and I'd bet you can find one there. Just be careful since they might be glass.
so um any ideas on this?
without paying $100
As far as constructing that axe... thing, corrugated cardboard and dowel rod for the base shape, craft foam to fine tune the shape, and poster board to make it clean will be your cheapest method. For something more difficult but with less material, you can carve down a block of pink insulation foam (Available at Lowes or Home Depot), but you can only buy a giant sheet of the stuff. When you carve it, the bits get staticky and stick everywhere, too. If it was me, I'd just opt for cardboard, posterboard, and craft foam on a dowel rod. You'll get it.
Joanns does sell a thick craft foam that cuts beautifully so long as you have a long enough blade that's sharp. As soon as it gets dull, the edges catch and the foam gets raggedy. Luckily it can be sanded with fine sand paper well enough. Drawback: if accidentally press your fingernail into the foam, that dent isn't going anywhere anytime soon.
Cardboard is one of my favorite cosplay materials, and I love working with it since it's cheap and easy (but not durable). Hot glue works great, and if you spraypaint it, just hit it with a primer/sealer like Killz then once dry, paint it whatever color your li'l heart desires.