I wonder if that English guy was me?! I was in Sumy from March 27th to April 4th.
I only noticed one other English speaking guy in a café, but I couldn’t hear him properly, I think he could have been German using English to communicate.
I flew in via the city airport Zulyany, I returned via a taxi mini bus (Mercedes Sprinter). 100 Hryvnia to the buss stop at the railway station, and 60 Hryvnia from there to the airport by taxi. A free taxi was included from my apartment to the mini bus. The mini bus made a couple of stops on the way, one near the airport at Borispol. Total travelling time was 5 hours.