In Togo 1€ = 655,957 CFA Francs
Flight: To be seen according to the companies, before it was between 400 and 600/700€ return, today with the health crisis the rates are very very variable.
Advice: make sure to take a ticket with a cancellation and modification option.
Estimate for your personal expenses (outings during the week-end, souvenirs, telephone, Internet...): from 200 to 350 € per month, depending on your needs (it also depends on what you want to do)! Plan a reservation in case of medical expenses. This estimate is really approximate!