UPDATE 2021-08-27 15:27 +0300: I am back with a new desktop computer. No local provider has any, while online offers, such as on ebay, have exorbitant shipping costs (e.g. EUR 40-60 for the battery and over EUR 100 to send it to Cyprus). The donation money changes my plan A: I will search for hardware to either build a desktop computer or buy a mini tower.