Hello, Philippe,
I understood from Keegan that you want me to suggest adapted donation sums for the BG version of the landing page. I would suggest 100, 50, 20, 10, 5 (if there is possibility for fifth option) or (if not) only 100, 50, 20, 10. The word "Other" translates as "Друга сума" or - if it's needed to be short - "Друго".
Thank you in advance! Vassia