Rick's travel guide makes a point of the value in the Athens Combo Ticket. Five sites in one ticket bundle. You can buy one in February, and in March. But it seems they will go away after 31 March. So you can't buy one in April, or in May, and probably not in June, July, August, or in September when I'll be traveling . . .
I'm wondering if, now that the days of the Travel Pass are numbered, travelers have identified other ways to efficiently obtain admissions to multiple sites once the Combo Ticket is no more.