He likes to cite random numbers, it seems. But in this case, I can fathom where these $500B are drawn from: Trump appears to add direct "Ukraine aid" (most of it, alas, highly likely has been stolen or just left to circulate inside the US MIC anyway) and these American business' losses after the partial decoupling of Russia, about $300B, which Kirill Dmitriev has shown to Rubio. Suspiciously enough, the latter number coincides with the sum of Russian frozen assets abroad.

I doubt, further, that Russia concedes $300B simply as a payment aimed at post-ceasefire Ukrainian reconstruction. The colossal geopolitical rapprochement which Trump has initiated just urges Kremlin to demand better conditions of the settlement. More likely, the US will obtain ROU assets in exchange for a share of Ukrainian mineral wealth that is currently unreachable to Kiev (4 partially annexed provinces). After this, US may get their brokerage, say, 50 % or even 75 % (which will depend of avarice, stupidity, and hauteur of Zelensky), while the rest may be placed into the fund created specially for the rehabilitation of Ukraine, under the most strict control directly from Trump-Vance-Musk's administration. Speaking about Zelensky and his cronies, I think they have little choice but Hobson’s. Zelensky has nobody to blame for it but himself, Boris Johnson, and Biden-Harris administration: the war could, and had to, be shut down already in Istanbul.

All in all, it looks like the gears and cogwheels of the Russo-American Détente are gaining speed.