No No No.
They changed the logic sometime ago where Gold or GPT and a city are involved. The notion of trading citizens for cash is a bit too mercenary for them, I guess.
It also allowed you to use a city as a Trojan Horse. Populate a city in a 'culturfied' border area, sell off the temples, trade it for a lot of gold/tech and then wait for it to culture flip back.
Since adding gold goes from maybe to no way, I'll bet a city is involved.
It makes sense overall, but the rule is WAY too strict. You cant even offer one of their own captured cities back in exchange for mucho gold. In the interest of protecting their people, they should jump at the offer.