So in the picture we have what appears to be a sale, but after doing some math, it's not really a sale at all. 180 Manda wouldn't give you 1400 to begin with. Fuel is 60 per 5 Manda, so, let's do some math!
180/5 = 36
36x60 = 2160!
So for 180 Manda, I should get 2160 fuel, but alas, this sale generously drops the price down to 116... But let's do some more math.
116/5 = 23.2
23.2x60 = 1,392...
So basically you're getting almost exactly what you're paying for. Except for a free 8 extra fuel thrown in.
So this raises the question, why have the "original" price at 180 if you're only going to bring the amount you buy down as well?
"You can buy a dozen eggs for a dollar! Or, for 48¢, you can buy 6 eggs, but only once!"
Edit: alright, considering the amount of fuel received and also the fact that it doesn't go toward the daily fuel purchasing amount (a limit I had totally forgotten about) this is a good bit more reasonable than at first glance.