Trying to create a formula that changes the calculation once the answer reaches a certain value but applies the original calculation up to that point

In this scenario I am creating a google sheet calculator that assumes a certain calculation up to the value of 3000. Anything over 3000 applies a different calculation BUT the value generated up to the 3000 remains with the different calculation only applying to everything above the 3000 mark and is in addition to the original calculation.

=IF(C6<=3000,($E$1/$B$2)*C6,IF(C6>3000,C6))

The challenge with the above formula is that as soon as the answer is above 3000 the IF(C6>3000,C6) is applied to the entire number.

Any help would be greatly appreciated.