Slitherine

Still having problems with upgrading units. The file is too big to attached, so I have emailed it to you.

The city of Phoenix in hex 2, 48. There is a Hurricane Aircraft. To upgrade it to the latest equipment costs 1944 credits. To buy a new Hurricane Aircraft with the latest equipment costs only 1275 credits.

To help alleviate the problems with upgrading, perhaps instead of purchasing the upgrade one could place it in a city and have a cost in turns to upgrade. As an example, if it takes 6 turns to build the new unit, have it cost 3 turns to upgrade the unit. Just some food for thought.

That's because your city is overflowing with production so much that you have left-over production that is used to build a big portion of the aircraft before purchase.

The normal cost for it is *8 of the production cost. So in your case (-25% from advancement) 504*8*0.75=3024.

OK, I can understand what your presenting, but it still doesn't make any sense to have the upgrade cost more than the new unit. There is no point in upgrading a unit when it is actually cheaper to build a new one. I have been playing around a bit and have found that I can simply sell the old unit and then reduce the net cost of the unit even more. Why not allow the left-over production you mention be used to reduce the cost of the upgrade?

Would it be possible to give the player the option of purchasing the upgrade or as I mention in my original post allowing the player to use production to upgrade the unit?

I think what he meant by the cost is that, in your city there was left over from a previous construction, so buying it substract from that left over.
Correct if I'm wrong but, the cost from buying is something proportional to the overall cost of unit+parts, while refitting is proportional to only the parts changed.
The refit of units has been very cheap for me, and added to that, the unit remains ranked with experience, which is a huge advantage.

Indeed. Check a city with low production, it should cost a lot more.