Add 100 only if greater than 5200 (condition); Keep the same value between 2 values.

Hello!
Can somebody help me?
I already have TWO formulas in two cells (columns):
Column 1) =IF(AF1695>=5200,MAX(150,ROUNDUP((AF1695-200)/25,-1))+100,MAX(150,ROUNDUP(AF1695/25,-1)))
I would like to update this formula with the following conditions:
* If 7450<AF1695<=8950, cell result to keep fixed, to remain the same as the value of AF is 7451.
* If AF>8950, cell value to increase proportionally again, but with +50 instead +100. ((AF1695-200)/25,-1))+50
Column 2) =IF(AF1695>=5200,MAX(150,ROUNDUP((AF1695-200)/25,-1)),MAX(150,ROUNDUP(AF1695/25,-1)))
I would like to update this formula with the following conditions:
* If 7450<AF1695<=8950, to add in the Column 2 the value wich is not added in the Column 1 (because its value does not increase)
* If AF>8950, cell value to increase proportionally again, with +50. ((AF1695-200)/25,-1))+50
EXAMPLE;
AF value is 7450; result AY(Column 1) value will be 390 and BC(Column 2) value will be 290
AF value is 7451; result AY(Column 1) value will be 400 and BC(Column 2) value will be 300
AF value is 7800; result AY(Column 1) value will be 400 and BC(Column 2) value will be 320
AF value is 8000; result AY(Column 1) value will be 400 and BC(Column 2) value will be 340
AF value is 8300; result AY(Column 1) value will be 400 and BC(Column 2) value will be 360
AF value is 8500; result AY(Column 1) value will be 400 and BC(Column 2) value will be 380
AF value is 8800; result AY(Column 1) value will be 400 and BC(Column 2) value will be 400
AF value is 8950; result AY(Column 1) value will be 400 and BC(Column 2) value will be 400
AF value is 9000; result AY(Column 1) value will be 410 and BC(Column 2) value will be 410
AF value is 9300; result AY(Column 1) value will be 420 and BC(Column 2) value will be 420
AF value is 9500; result AY(Column 1) value will be 430 and BC(Column 2) value will be 430
AF value is 9800; result AY(Column 1) value will be 440 and BC(Column 2) value will be 440

And so on...

Thank you very much!