Make it possible to change price of a expense

[diasDominik]

Is your feature request related to a problem? Please describe.
I want to change the expense for e.g. next occurence but want to keep the history of the expanses.

Describe the solution you'd like
a possibility probably a other dialog to edit the expense to make there a start date when the expense changes.

Describe alternatives you've considered, if any
alternative would be then to change the expense but with this the calculation of the hole year and therefore the month also changes.

[825i]

Yes it would be great if we could eg. add a price increase to take effect next month.