It is not a gift so they can't do that and certainly won't since they want to get a tax deduction as an expense. You should speak with a CPA to see about options to reduce tax liability.
This answer is for informational purposes only and is not legal advice regarding your question and does not establish an attorney-client relationship.
There are several issues that you should be aware of in this transaction. This forum does not permit the thoroughness that's required to answer your question.
I would be happy to offer a free consultation to you at your convenience.
Andrew M. Bonderud, Esq.
The Bonderud Law Firm, P.A.
Andrew M. Bonderud, Esq. is an attorney The Bonderud Law Firm, P.A. He offers free consultations 24/7. Andrew's posting here is not to be considered legal advice nor does an attorney-client relationship exist.
For this amount of money I sure hope you are going to hire a professional to assist you with the contract between you and the buyer. A business lawyer with tax experience on structuring ideas would serve you well since a CPA will not be able to draft/edit your contract memorializing the agreed upon deal structure for your patent. For example, you could license your patent to the buyer instead of selling it and obtain a royalty for some period of years based on the sales volume which can create an annuity stream for you over many years. You could structure it as an installment sale with X$$ as a down payment with balance spread out over several years to minimize the tax impact in first year. You could do a combination of the license and sale transaction or even couple an option to buy being issued if the buyer achieves certain sales levels over a period years where you were obtaining a royalty. Capital gain tax rate vs. ordinary income tax rate also matters in the structuring for buyer and you (as seller or licensor).
My answer is not intended to be giving legal advice and this topic can be a complex area where the advice of a licensed attorney in your State should be obtained.
The question first of all is why you would take the money if you could simply patent the idea itself and likely receive even more money. That aside, the transaction you speak of is fraught with numerous IP, tax and liability issues that will require a skilled transactional attorney as well as one who works in IP. There's likely some financial planning that will need to go on as well with an accountant or financial advisor. My firm does this sort of work, but it is not cheap. You need to hire someone to handle this correctly or you will be paying for being "penny wise pound foolish" for years to come.
The foregoing is not legal advice nor is it in any manner whatsoever meant to create or impute an attorney/client relationship.