What is the optimum way to do Secret Santa with kids?

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What is the best way of arranging a secret Santa to buy for our kids to save us from having to buy for them all?

My friend group consists of 8 friends and 16 kids.
2 friends have one kid. 4 friends have two kids. 2 friends have three kids.

Option A: each adult picks two kids and spends £20 per kid, a total of £40.

Option B: each adult picks for a “family of kids” and spends a total of £40. So one friend may just buy one kid a £40 present. One friend may buy for three kids, spending £13.3333333 on each kid.

Option C: each adult buys for the total number of kids they’ve got. So the parent of three kids buys three presents and spends £60. The parent of one kid buys one present and spends £20.

Supplementary questions:
SQ1: does your answer change if there are 8 friends and 17/18/19 etc kids
SQ2: is it reasonable to say “shall we just bail out on this idea if we can’t even work out a way to administer it”?

B or C.

I’d probably go for option C personally. We’ve done something similar where the kids picked a name and then brought a present for that child (obviously it was the parents that paid). This is largely the same as option C.

Thanks! What rules out A?

C is the only real ‘secret Santa’ and the fairest way to split it. Use ‘draw names’ or another similar site. You can put in caveats so siblings don’t buy for each other. All the children then a child to buy for and they all receive a present (you can use the parents email addresses), it stays secret so even the organiser doesn’t know who has got who.

I'd have gone for C, if effectively a secret santa between the kids this would mean that each child then had someone to buy for (and the adults put in what they take out).

Option A would seem harsh on the one child families.

I think C. In our family once you are 18 you are out though

Option A means those with fewer children than the average over-contribute and those with more under-contribute.

Option B means that children who are part of a larger sibling group are unfairly penalised for their parents' reproductive choices by missing out on present value.

Option C is fair - each family group contributes in proportion to what they wish to receive, and the children all get presents of equal value.

SQ1: No, for reasons above.

SQ2: You're not obliged to do it at all, so not unreasonable not to.

Thanks! I hadn’t considered that we C is more true to “Secret Santa”. The kids are so little at the moment but they won’t be forever, and this way we’re setting up for when they pick the present for their friends.

With option A do you mean they’re spending more than they’re getting in return?

D) each child gets a very small "personal gift" which might be some consumable/stationary item 1-2 £/each.
Every family picks another family and gives them a family gift, which will be shared by all children in the family and can be something more substantial.
That way all families are putting in very similar money and getting a similar value.