This blog post offers strategies for LC on a budget, you may need to modify some recipes to fit in your keto week depending on your daily carb max. I would likely add more fat. The blog post points out this is not Paleo or Organic, but if you have an Aldi near you could get closer on the organic
http://healthteamadvisor.com/budget-low-carb-25-seven-day-meal-plan-recipes-three-meals-daily/