Yes, Red Harvest, the absolute necessity to construct a flat "runway" for the siege tower is an often-missed aspect of siege warfare in historical games/movies.

Also, a siege tower was in the beginning a major undertaking. To have just 1 was difficult and expensive enough.

ER: Yeah, that's what I was looking for!

Now all we need is to find a way to insert the "siege point" price per item. Is there anywhere to do that?