Just want to share our this morning experience to the airport.
We stayed at Ferenciek Tere area, it was about 5 minutes walk to the metro station. It was about 4.15 am, we arrived at the metro station and the gate was closed, there were quite a few passengers waiting outside the gate. At 4.30 am, the staff came to open/unlock the gate, and we all went inside and took the escalator down to the waiting area ..and about 5 mins , the train came. It was the first metro train that we took. (Line M-3).
About 20 -25 mins ride on the metro train, we arrived at Kobanya-Kispest. We walked out of the metro station, there was a sign where we could take the bus 200E.. So very conveient formud...just walked to he bridge and took,the escalator down, , and the bus was below waiting for the passenger...i Got the the bus and ride to the airport...very pleasant experience.Arrived at the airport about 5.15 am.
Btw, we bought the metro and bus ticket at the BBK customer service office it was 530 HUF including the transfer to the bus,,,
Hope this help to other travellers...