Just to make sure I understand you correctly, you are using “evolutionism” here is the same sense as scientism? - Is that correct?
Ham contracted Nye for the debate, paying Nye an appearance fee. IIRC this comes from Nye’s agent. I will let you google this one yourself, and I’ll get the next one…
The following are facts: Ham was well below his donation goal to start construction on his Ark Park. Ham lost money on the ticket sales from the debate itself, as they were not enough to cover Nye’s appearance fee (and Ham gave away a lots of tickets too). Ham/AiG is believed to have recouped the loss and probably turned a profit on DVD sales. Following the debate a wealth donor provided the money that allowed Ham to proceed.
— The details about the donor’s conditions leading to the debate I will need to look up, but it was much discussed at the time. I will google for sources when I have time, and edit to include these below.
edit1: This Wiki article confirms some (not all) of my claim, and is well sourced.
edit2:
Those registering for the debate’s live online stream topped 800,000 two weeks before the event, for which the museum is paying Nye expenses plus a fee. The museum would not disclose the fee, but Nye’s normal speaking fee is $50,000 to $75,000, according to Celebrity Talent International [source linked].
edit3:
In early January 2014, only $26.5 million in bonds had been sold; if at least $55 million in bonds were not sold by February 6, all of the bonds would be automatically redeemed.[33] On February 27, 2014, AiG founder Ken Ham announced that his February 4 debate on the viability of creationism with TV personality Bill Nye “the Science Guy” had spurred bond sales, and that the Ark Encounter had raised enough money to begin construction.[34][source] and another [source]
What remains to show for my claim is that a single wealthy donor contributed a substantial part of the $24 million needed at the time of the debate. I’m out of time to pursue this further at the moment.
edit4: This is not the smoking gun I was looking for, but may be as close as I can get:
A few weeks after the debate, Answers in Genesis held an online event in which they announced that they have or had raised the funds for their amazing “Ark Encounter” theme park, or “Ark Park.” I posted a tweet on the Twitter social media site, “Here’s hoping voters & journalists wonder: where did all those $ millions come so quickly? After a deadline?” Soon after that, Mark Looy of AIG sent an email to my office assuring me that the bonds had already been secured, before Feb. 4, i.e. before the debate—and before the unrated bonds’ deadline. I could not help but notice that Ken Ham made no mention of this during our encounter, i.e., during the debate itself. I also could not help but notice that his colleagues suggested that the debate helped close certain aspects of their Ark Park deal, later during their online event—at which not a single journalist, or anyone else for that matter, was present. These are details, but it does make me wonder, who donates those millions? I wonder if one project is leveraged against the other. I’ll leave it to the Kentucky journalism community to seek answers in this funding genesis.[source]
My emphasis added.