如果专利权是从他人手中购得，那么其成本就是购买价格。

If a patent is purchased from others, its cost is simply the purchase price.

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专利权有效期限届满或者专利权被宣布无效的，专利权人不得就该专利与他人订立专利实施许可合同。

If the valid duration of the patent right expires or the patent right is declared invalid, the patentee may not conclude a patent exploitation license contract relating to that patent with others.

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但是因专利权人的恶意给他人造成的损失，应当给予赔偿。

However, the damage caused to other persons in bad faith on the part of the patentee shall be compensated.

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