Cost of US-Mexican Wall construction

That would be great. Thank you.

We can cancel this one and you can recreate the prop if you'd like with what you wrote below.

... So to solve that I think the best way is to remove the option whether they build the wall or not, and let the bet simply be about the official projected costs at the first official presentation of the plan by the US government.

Although for that last comment, I foresee another issue where they present the plan and the costs but then get in limbo for some time while trying to get funding approved, and during that time basically 2 out of the 3 price options will be irrelevant and it'll be between Not Built and one of the price options, thus making it illogical to place and earlier bet and simply wait until that it known. ... See followup in next comment.

And for the case that they present the plan and costs of construction but don't get funding approved and don't get to start building the wall yet by the end of the deadline of the bet, this qualifies under 'The Wall is not built'.

So I think a better way to phrase the decision logic is that the bet ends when the official project's plan and costs are announced by the government, and not what the costs of the project are at the end of the deadline of this bet.

The issue is that once the plan has been presented and they start building the wall, they probably won't make any adjustments in the official project costs before the end of the deadline of this bet. So let's say they announce the project and the costs of it halfway into the year, the outcome of the bet is unlikely to change from that point out because any adjustments, like it turning out to be more expensive than anticipated, won't be announced for at least like a year after.

We read your determination change request... so the issue is that you probably won't know the real cost even once building starts. It may be years before you know the real cost. Also, the cost will be subjective and depend heavily on the source used.. not sure this prop will come to fruition unfortunately..