I've had the same .org domain for around 15 years now. Except for the coup we've seen last year where somebody tried to buy it privately (thankfully averted, I believe), I've see no price hike over time.
That part is probably not a good bet, as life can go in unexpected directions.
Some country providers (eg .eu) only provide service to their citizens, so if you move country or otherwise become "not a citizen" they'll terminate your domain. As happened recently to the UK holders of .eu domains. :/
Probably better to pick a .net/.com/.org domain, for (hopefully) longer term stability.
Also .org falls under US influence, which may not have worked out so well had you been making this decision in Ukraine a decade ago
Very much agreed on .org.
[0] https://www.iana.org/domains/root/db/eu.html [1] https://eurid.eu/en/register-a-eu-domain/brexit-notice/
Ahhh, hadn't realised that. Though I'd suspect .com and .net would be in the same position as .org in that respect.