Dragon Rising, are the Red Enveleope buildings underwhelming?

[SASgold]

After checking the purchase options using Red Envelopes, I think the coin yields are remarkably low, aren't they?

Statue of Wealth (750 envelopes) - 1x1, 6 coins every 1h, MaxPop +3 and 3 Electricity
Money Tree (2200 envelopes) - 1x1, 10 coins every 4h, MaxPop +5 and 2 Electricity
Dragon Gate (3700 envelopes) - 1x1, 10 coins every 4h, MaxPop +10 and 3 Electricity
Emperor's Tower (11000 envelopes) - 2x2, 15 coins every 8h, MaxPop + 15 and 7 Electricity

For example the Golf Club (same size and electricity) compared to the Dragon Gate gives 3x the amount of coins per 4h as well as an 1 radius 3% passenger bonus, although at a relative 16 Population decrease (consumes 6 instead of granting 10)...

 

[exwhy]

Those are indeed underwhelming and generally, coin buildings are not worth the land space once you need to build pax buildings for flights. Better to use envelopes to buy repair item or flight item sets.