Covering is not cheap. Some of the ARF factories use film covering that is not Monokote or Ultracote to save money.
Even the ones who do use the "name brands" probably get a huge discount for buying a lot.

You'll probably need 2 rolls of your primary color and 1 roll of a contrasting color.
at www.greathobbies.com
-Ultracote is 18.99 to 24.99 per roll
-Monokote is 14.99 to 19.99 per roll
-Worldtex fabric covering is 27.99 per roll