Obviously, there is a lot of minutae that would need to be worked into something like this, but do you think it's something that would benefit the current owner as well as the future owner?

As far as enforcement of the agreement, since the chip owner would retain possession for some time, I would think that, should the original chip owner fail to perform (ie, deliver the chip/collection), the buyer would be entitled to get his money back (with a penalty and/or interest).

A clause could be included wherein the chip owner could be allowed to back out of the agreement if they choose, but they'd again pay a penalty (same as a lost or stolen chip/collection).

On the flip side, if the buyer doesn't pay (in full up front) or fails to make timely payments (if that's the arrangement), the chip owner is certainly not under any obligation to transfer ownership of the chip, and if enough time elapses without payment, the chip owner could opt to cancel the agreement with the penalty being partial or complete forfeiture of the monies already sent by buyer.

The contract can/should be notarized (if the amount in question is significant to warrant it) and a copy given to the chip owner's attorney as well as the executor of the estate. I suspect one could even put a lien on the chip or record the agreement in whichever county has jurisdiction over such matters.

The question of "book value" may arise as well, as the value of the chip may rise or fall over time prior to the time when the chip is to be transferred. One or both parties may wish to have a clause that allows/prevents them from participating in the increase or decrease in value of the chips under contract. I would think that most people would simply make the deal based on today's value and let the chips fall where they may, but anything that can be contested, may be contested, so best to put protections in place to pre-solve the problem.

I could probably think of more examples and solutions, but that's enough for now, I think.

Thanks for replying and let me know more of your thoughts if you have any on the matter.