Yes and no, May is usually more expensive, but there's also the aircraft occupancy rate. If the plane isn't full, prices go down, and occupancy is determined closer to the departure date, not three months in advance. So, I think it's theoretically possible to snag tickets from Yekaterinburg for 3-5 thousand rubles round trip, but I also think that 6 thousand rubles round trip is a good deal.
And for those who are slow on the uptake, I can't possibly get from Odessa to Moscow using the Yekaterinburg-Moscow flight.
