What is the origin of the custom to have kids find the afikoman?

Question

The instructions for yachatz in every hagadah that I have seen say to break the middle matzah in two (though, the thin paper hagadah I used in elementary school said, "break in half") and put the bigger piece (the school hagadah said "bigger half". It was only years later that I realized this is impossible!) away for the afikoman.

No instruction I have seen said anything about hiding it or having kids look for it and then "bargain" for a present or prize in order to return it.

So, when and why did this custom originate? Is there any Rav who may have been against this custom, perhaps, because of the scenario I mentioned or some other reasons? Personally, I felt extremely uncomfortable with the price bargaining, esp. on a Yom Tov. It sounded like the afikoman was a business deal.

Answer 1

The custom is mentioned in the Chok Yaakov on Shulchan Aruch O.C. 472 s.v. 2 who suggests a hint from the Talmud (although he doesn't actually suggest this is what the Talmud means) and says the purpose is to keep the children engaged and awake until then.

The Chabad custom is to not do the stealing. The Lubavitcher Rebbe writes that the reason is to not give the children a taste of the "thrill" of stealing.

An alternative for your to consider (the custom in my family, actually): The adult does the hiding, and the "prize" is pre-arranged (lots of siblings, I suggest that all who are awake to search and do so be eligible). This has all the benefit without the attendant downsides.