Sounds fun! This is a costume that would be pretty easy to piece together instead of buying premade, so $150 is definitely plenty.
I'd start with a long sleeve unitard like this so you don't have to paint too much skin.
Ben Nye has got great body paints IMO assuming you don't have an airbrush. I used to LARP in full face paint, and I liked their aqua cakes . Your wife may already have a makeup setting spray to go on top, but if not make sure you get that too. :) Unless you're mixing colors you shouldn't need more than one large cake.
Aradani is a safe bet for quality ears. Get spirit gum and spirit gum remover along with your ears.
Now accents! You can get decorative chains in the trim aisle of a craft store like JoAnns, they'll be on a plastic wheel you take to the fabric counter to cut off how much you want. There are fun "ribbons" there too that you could easily make a fancy choker with like the one in your link--for the wrists it might be easiest to just buy some inexpensive gold colored bangles. Hit up a thrift shop for scarf accents if you don't have any, or just Google fashion scarves. :)
Hope that helps!