product_pricing_calculator.rb

BRAND_RATING_FACTOR = {:high => 1.1, :low => 0.9}
PRICING_REFRENCE = {15 => 0.75, 25 => 0.775, 50 => 0.8, 75 => 0.825, 100 => 0.85, 200 => 0.875, 400 => 0.9, 600 => 0.925}

price_reference = 99
product_database_shipping_cost = 50
brand_rating = 'high'

def get_pricing_ceil(price)
  PRICING_REFRENCE.find {|key, _| price < key}.try(:last) || 0.95
end

price_original = price_suggestion = (price_reference - product_database_shipping_cost * get_pricing_ceil(price_reference)) * BRAND_RATING_FACTOR.fetch(brand_rating.to_sym, 1)