My first self-made costume was probably over $100 once I factored in the fabric, lining, wig, shoes, piping material, ribbon, and makeup.
My first commissioned costume was definitely over $100 for the labour and I can't remember how much the fabric was.
My cosplays now are rarely under $100 unless I can re-use pieces like wigs, or they're closet cosplays. Fabric gets expensive when you start buying the higher-quality stuff.
Princess Bubblegum (Adventure Time)
Marceline (Adventure Time)
Suiguintou (Rozen Maiden)
Twilight Sparkle (Princess - My Little Pony)
Rest to be decided.