hooks.rb

After do
  MVOR.Postage.threshold = BigDecimal.new('6.99')
  MVOR.Postage.rate = BigDecimal.new('30.00')
end

mvor_postage.rb

module MVOR
  module Postage
    class << self
      attr_accessor :threshold
      attr_accessor :rate
    end

    self.threshold = BigDecimal.new('6.99')
    self.rate = BigDecimal.new('30.00')
  end
end

some_steps.rb

Given /the postage threshold is (.+)/ do |t|
  MVOR::Postage.threshold = BigDeimal.new(t)
end