Can we find out the amount Alex is willing to bet?

I think this is a matter of negotiation.

If both sides are willing, I'll gladly comment. I don't think Vitaly will object and will provide a stream. What about Alex?

Streams from both sides are a must; otherwise, what's the point?

But not for Alex's participation in the match (in my opinion, that's nonsense).

Don't confuse things – this isn't about paying Alex for participating; it's the prize pool that goes to the winner.

Personally, I'm also willing to contribute N amount of rubles for Gomunculus, according to the scheme proposed by Sticky. The question is, how much is Alex offering from his side...?

This should be discussed with the participants. That is, there are two possible options for the contribution:

1) Simply a contribution to the prize pool, which goes to the winner; I intend to do exactly that.

2) Backing – an individual bet with one of the match participants; the money goes either to this match participant (in case of his victory) or to the backer (in case of this participant's defeat).

And if there isn't, all the collected funds will go to Alex, as compensation for the trouble, as I understand it :)

The match will only start when the financial terms are agreed upon; no money will be moved before that.