Jets have an Offensive of 2 and 0 def
Tanks have 4 for both

So why do jets sell better than tanks?

Because they cost around 1/3rd to 1/4th as much as tanks but provide half the offense. And if you send your tanks out on a planned strike, they provide 0 defense.

That makes more sense :P Thanks

Also, when you attack someone and lose a tank, you're losing 4 off and 4 def = 2 jets AND 2 turrets instead of just 2 jets.

and much cheaper upkeep.

Upkeep:

Troops = $0.11 / turn / unit offensive or defensive power
Jets = $0.07 / turn / unit offensive power
Turrets = $0.09 / turn / unit defensive power
Tanks = $0.14 / turn / unit offensive or defensive power

i'm embarrassed to admit it but I didn't realize that either

Bobby you n00b, why do you think I cash 100% jets the last day of express as a C/I?

to make a big last min lg? :P

Let me clarify. My post addressed the cost of each unit per unit of offensive or defensive strength. If you want max defense for your upkeep dollar, buy turrets. Max offense, buy jets.

Upkeep by NW:
Troops: $0.22/NW/turn
Jets: $0.23/NW/turn
Turrets: $0.30/NW/turn
Tanks: $0.285/NW/turn

All upkeep costs are + food consumption. At $44/bushel, the extra costs are
Troops, jets, and turrets: $0.044/unit/turn
Tanks: $0.132/unit/turn

Factor that into the above values and the total upkeep per NW per turn for each unit is:
Troops: $0.308
Jets: $0.303
Turrets: $0.373
Tanks: $0.351

troops cost alot to keep rofl.

If food is at $44 including market fees, troops are the second least expensive unit to keep NW-wise. However, they're the second most expensive if you actually need them for offensive or defensive strength.

How much are spies upkeep?

Spies are $1/unit/turn + 0.005 bushels = $1.22/unit/turn @ $44/bushel. Spies are 1 NW so they're also $1.22/NW/turn.

Also, all of these numbers scale with NW which I factored out since it's a common factor along with gov't bonuses and tech %.

upkeeps are at ee-wiki: http://wiki.earthempires.com/index.php/Formulae