When I added more towers I had all my rooms, 84 of them, booked but that tiny bit of profit wasn't worth it. This was at moderate price for a room.
Your mistake is to set prices to moderate if all rooms are booked. When there is more demand than rooms you must raise the price; only if the demand drops you must do maths to evaluate when more rooms at cheaper price make more profit than less rooms at higher price. In a base general case, 84 moderate rooms generate more income than 63 expensive rooms in a Beach tower.
I know you don't like maths, but here are some:
To build a new beach tower cost $1,500 plus $5,000 plus $10,000 = $16,5000
Once build, your room capacity increases by 40.
The maintenance cost of the tower is $500
If you rent all the rooms at moderate price you get no less than 40x
31 = 1,240 - 500 = $740 profitability. In 16500/740 = 23 days it will return the investment.
If you rent all the rooms at expensive price you get no less than 40x
41 = $1,640 - 500 = $1,140 so you need 16500/1140=15 days to recover the investment.
But that's a base estimate. The amenities adds to the base income (the figures in green) and, for example, in my Hobart's Hideout I am making $71 per visitor each day. So my figures are 40x71 = 2,840 - 600 (maintenance with room service plus spa) = $2,240 per room per day. So I recover the investment of build one tower in one week.