Dinoarms, there is a LOT of discussion along these lines in the following post..search through it till you find the info you want...
http://apolyton.net/forums/Forum12/HTML/001640.html
The gist of your question needs to be refined. 'Cost' is expressed either in energy units or minerals in this case. If you are going to rushbuild your 2-2-2 unit vs. build a 1-1-1 and upgrade, you are talkng about energy credits and it gets a little complicated because each row of minerals in your production screen has a different cost when rushbuilding. The first row is the most critical. Those first 10 minerals (or 9 or whatever depending on your Industry rating) that make up your first mineral row are really expensive. Follow that post and you'll have all the info you need in that case.
On the other hand if you are talking about either waiting for 'normal' production to finish your unit vs. building a cheaper unit more quickly and then upgrading you are comparing apples and oranges and there is no 'cheaper'. If your goal is to get the unit out in the field, by all means build the 1-1-1 and then upgrade it. But, that takes two turns, one to build, and one to upgrade. Rush the production of the 2-2-2 unit if you can afford it and that only takes one turn. Many players seem to like to rush build toward the end of production when it is 'cheapest' in terms of energy spent per mineral developed, and indeed, that's what I do. After all, what else are you going to do with those handy energy units? Hope this is some help. Experiment! That's the best way to answer your own question.
-Smack
. Thread moved.
