def guide_with_prices(guide_with_numbers):
    """Supply an instance of Guide with some defined numbers and prices."""
    values = (
        (("Silver", "Rocks"), 36.0),
        (("Gold", "Rocks"), 136.0),
        (("Silver", "Coins"), 5.0),
    )
    for pair, value in values:
        guide_with_numbers._parse_price_definition(["i", pair[0], "is", value, pair[1]])
    return guide_with_numbers