"They are very generous/favorable/reasonable/affordable" 是对 "他们非常优惠" 的英文翻译。
来源：这些词都有 "优惠"、"合理"、"实惠" 的意思。
例句：
They are very generous with their prices.（他们的价格非常优惠。）
They are very favorable in their terms. （他们的条件非常优惠。）
They are very reasonable in their charges. （他们的收费非常合理。）
They are very affordable for most people. （他们对大多数人都很实惠。）