And, what if they had demonstrated their cool raygun to you before offering to trade the 4d trinket for your house? Maybe you can at least trade the trinket for a smaller house in a worse school district, and that would be preferable to the indirect possibility of being disintegrated.
On the other hand the trinket might really be more valuable than your house as exposure to some technology that doesn't exist in the economy where you live. Or, trading coffee was equivalent to smuggling silkworms out of China. Or, you sold them the Brooklyn Bridge rather than coffee or your house.
This moves the goalposts though. Before the ethical question was whether or not it is ethical to trade items with unknown value to a less advanced group. Now it's whether it is ethical to do so under threat of violence (obviously unethical).
On the other hand the trinket might really be more valuable than your house as exposure to some technology that doesn't exist in the economy where you live. Or, trading coffee was equivalent to smuggling silkworms out of China. Or, you sold them the Brooklyn Bridge rather than coffee or your house.