I just sold a miyata 910 and fund a new 5 speed cassette 17,19, 21 ,23, 25
Cannot tell who made. What is it worth?

Hard to say, I would guess either $350 or $3.50. Maybe somewhere in between.

Temper, temper, SweetLou.

To the OP: No one is going to be able to answer this question regardless of how much information you provide, because it depends on the market. Asking this question and providing no information will just tick people off or get you ignored, because that is troll behavior in this forum.

If you are interested in knowing more about what you have, provide clear photos and as much information as possible.

Temper? I have no temper or meant anything other than without any information, it is impossible to even try to guess a value.