Just got back from bandung early sept.
Word of advice when going to Tangkuban Perahu. There so many seller will follow you. Dont buy, just ignore and bear with it haha. (Stuff they sell beganda-ganda expensive.not sure about the gerai tho)
Also a few claim they are guide appointed by government (dono true or not) but when you talk to them they will try to sell too.
Conclusion just ignore anyone who aproach n enjoy the view as much as u can.