A few days ago there was a question - or rather a statement - that bus tickets for Tel Aviv can't be bought on the bus but must be purchased beforehand.
Today I went to investigate, and as I thought (and wrote then) it's a temporary thing, only for the summer. There's an Egged employee sitting right at the departure gate with a cash register/ticket machine, so you don't have to go to the main ticket window and line up for ages. In answer to my question he said it's only until the end of August.
Tickets for other destinations can be bought as always on the bus.