I used paint sample swatches from my local hardware shop. Now I'm not saying you should go out and raid their sample collection but 'ya know if you see a few that might come in handy or you have a stash that's been sitting around collecting dust, by all means, get crafting people.
I didn't have a butterfly punch so I ended up buying this small one for a special thirteen year old, I happen to know, who is "totally" into butterflies and loves the colour blue. I used a basic punch because I didn't allow time to find and purchase a larger, nicer one but this one did the job. I'm on the look out for some good quality, larger punches for future projects.
My largest expense was the shadow box frame which I purchased at our local IKEA. I love IKEA! I didn't even use cardstock (should have, I know!) for the base page to adhere the butterflies to. I didn't have any on hand so I used the sheet that came in the frame and it turned out fine. I did use small foam dots. Hard to see but the butterflies are all slightly raised which gives it a nice effect. I think I could have fit another row & column of butterflies in there as well but it was my first, so next time.
Little "Miss Butterfly" was pleased and that was all I needed to know that it was a success.