- Buying a red dragon costs 2468 gold, plus 17 upkeep for 4 turns. Thus you loose 24 and gain only 5 points for one Level5 unit. The second dragon, being 4/5 produced, does not bring anything (am I right here?!).
- Buying spiders plus their upkeep costs 920 gold, i.e. 9 points, while you gain 8 points for the four 2 level units produced, so a net gain of -1.
- Buying a heavy infantery plus upkeep for the remaining 9 turns costs 380 (= 200 + 4 * sum [0,1,1,2,2,3,3,4,4]), so you loose 3-4 points in gold and get 9 points for level 1 units, i.e. a net gain of 6 points
The real question is: can one red dragon bring you 28 points in just 5 turns?
The dragon options looses 19 points, plus the 9 points that you would gain by choosing the heavy infantry option. That would mean that the dragon must help you take at least one city away from the enemy, that you would not be able to obtain otherwise, to just break even.
I think the linear 1 point per unit level is a bit off, and there should be more points for higher-level units, representing their actual strategic value. Similarly, the points for gold should reduce slowly as the gold amount increases, i.e. 20 points for 2000 gold is fine, but then maybe 36 only for 4000 gold, etc. Another thing is unproduced units: it might be worthwhile to delay so that you get to have the last turn, so that the enemy loose one full round of production - especially if the enemy then has lots of unfinished units in production. I think this can be huge.
What does anyone else think? Are you altering your game strategies during for season's end?