How to i18n dropdown menu values. populated from database table

I have cargo form with dropdown menu in simple_forms, which is
populated from model cargo_price:
<%= f.association :cargo_price, :label_method => :price, :value_method
=> :id
%>

There is model called cargo_price with only ID and price columns,
*price
*column has 3 values (these values are populated to dropdown menu via
that
association) . I would like to i18n this populated menu. Is there any
best
practice for such a case? I tried without success to put translation to
yaml file:
en:
simple_forms:
options:
price:
allin: ‘All in’
pp: ‘40 PlusPLus’
makeoffer: ‘Offer’

thanx a lot