Cupcake Wrappers Cheap

300-400 Cupcake supplies/recipe?

I am running for Stundent Council. If i win then I need to back about 300-400 red velvet, chocolate, vanilla Cupcakes. (about 100 each)
Can you recommend any good quality, cheap brands for cake mix, frosting, and the cupcake wrappers thingy. I need things that are pretty cheap, taste good/are good quality. and also could anyone give me a recipe? like:

As far as cheap, taste, and ease go, you’re best off buying any cake mix and supplies from smart and final or Costco. Don’t make all the batter together though because for some reason doubling recipes makes the cupcakes come out weird. To make it easier though pour the batter into a pastry bag and squeeze it into the cupcake papers

Dress My Cupcake – Cupcake Wrappers by KOYAL WHOLESALE Wedding & Event Supplies